THE PROHIBITION SUSTAINABILITY ON MARRYING A WOMAN OF THE SAME ETHNIC GROUP AS AN EX-WIVE IN MINANGKABAU’S TRADITION

: Marriage customs in Binjai, Pasaman Regency, differ from those in other areas. A man is not permitted to marry a woman of the same ethnicity as his ex-wife. According to Islamic law and Minangkabau customs, this prohibition on marriage limits a widower's opportunity to marry a woman of his choice. The aim of this paper is to investigate the origin and purpose of the marriage prohibition in Nagari Binjai, as well as the perspective of Islamic law on this provision. Traditional leaders (datuak), religious leaders, and the community provided the data for this study. Simultaneously, data was gathered via interviews, which were then analyzed using descriptive methods. According to the findings, the origin is the Nagari Binjai customary ancestors' agreement that a man who marries a woman of the same ethnicity as his ex-wife is treated as a relative or referred to as the same mother (samamak). Their marriage is expected to cause discord among tribe members, effectively ending their relationship. According to Islamic law, this prohibition is classified as "urf shahih" because the goal is to create "maslahah" among the local community, i.e. to maintain good relations between tribe members.

This study aims to provide insight into the causes of the persistence of customary provisions that forbid men from marrying women of the same ethnicity as their ex-wives. In this study, two questions are raised. First, why are marriages of the same ethnicity (sasuku) with ex-wives prohibited in Nagari Binjai, Tigo Nagari District, Pasaman Regency? And what is the Islamic legal perspective on this prohibition? These two questions will direct the writer to gather relevant data and discuss it to answer the questions outlined.
This article is based on arguments such as the fact that Islamic rules prohibiting women from marrying men are clearly stated in QS al-Nisa, verse 23. The Prophet SAW's hadiths have also provided additional explanations, such as the Prophet SAW's explanation that the rules regarding prohibition (marriage) due to lineage are the same as those that apply to breastfed people. Similarly, the prohibition against mixing a woman and her aunt (in a polygamous marriage). In terms of the marriage prohibition in Nagari Binjai, none of them adhere to the guidelines mentioned by Allah and His Messenger. Nonetheless, this rule has persisted to the present day and is supported by all traditional leaders and local religious people.

II. Research Methods
In this study, the researchers use field research with qualitative methods. Qualitative research produces and analyzes descriptive data, such as interview transcripts and observations. The researchers also employ library research with a normative approach. The purpose of normative legal research is to discover the truth that will be used as a building norm 11 . In this case, the norms of Islamic and positive law apply, as do the rules. According to Soerjono Soekanto, legal research is a scientific activity based on specific methods, systematics, and ideas that aim to study a particular law by analyzing it 12 . The type of data gathered during the research answers the questions posed by the problem as stated in the objectives 13 . The kind of data used to support this research is qualitative data relating to the background of the prohibition of marrying the same ethnicity with ex-wives in Nagari Binjai, Tigo Nagari District, Pasaman Regency, West Sumatra Province, the impact of the prohibition, and the view of Islamic law on the prohibition of marrying the same ethnicity with ex-wives in Nagari Binjai, Tigo Nagari District, Pasaman Regency, West Sumatra Province.
The data for this study came from community leaders, clerics, and Nagari Binjai society in general. In-depth interviews and observation were used to collect data. In-person and telephone interviews were conducted about the problem under investigation. Observations are made to learn about human behavior as it occurs in the real world 14 .
Following data collection, data analysis is performed in stages, beginning with data identification and classification and progressing to deductive analysis, concluding general knowledge whose truth has been recognized in specific conclusions. In this case, the researcher describes various types of marriage prohibitions in Islam, as well as the prohibition on marrying ex-wives of the same ethnicity in Nagari Binjai, Tigo Nagari District, Pasaman Regency, West Sumatra Province. In addition, researchers use the inductive method, which involves drawing broad conclusions from the specificity of the tradition.

The Prohibition of Marriage in Islam
Marriage comes from the word nikah, the arabic ( ‫,)نكاح‬ which means gathering, and entering into each other, and is usually also interpreted as having sexual intercourse (wathi'). According to the terms of Islamic law, marriage is a contract that is stipulated by syara' to allow men to have fun with women and to justify having fun between women and men 15 . According to Hanafiyah scholars, marriage is a contract that intentionally functions as "mut'ah"-a man can dominate a woman and all her limbs to gain pleasure and satisfaction. Accordingly, the Syafi'iyah scholars define marriage as a contract using the verb "zawj," which means to own. With marriage, a person can enjoy and get pleasure from his partner. Malikiyah scholars say that marriage is a contract that contains the meaning of mut'ah, to achieve satisfaction without requiring a price. The Hanabilah scholars say that marriage is a contract that uses 'nikah' or 'tazwij' to get pleasure. A man can get satisfaction from a woman, and vice versa. In this sense, "ownership" means the right to own through a marriage contract. Therefore, husband and wife can benefit from each other to achieve living in the household, which aims to form a family that is "sakinah", "mawaddah", and "warahmah" in the world 16 . Thus, in principle, there is no fundamental difference in the definitions mentioned by the scholars above, which generally define marriage as a contract (transaction) to obtain lawful "mut'ah" (pleasure) between a man and a woman by performing intercourse and other pleasurable acts.
However, not all women may be married to a man, who, in general, can be categorized into two groups: "mahram muabbad" (perpetually forbidden) and "mahram muaqqat" (temporarily forbidden to marry). The prohibition of "muabbad" is caused by several things, namely, bloodline relations, inbreeding, marital relations, and a "li'an" oath. Prohibition because of lineage is mentioned by Allah SWT in QS al-Nisa's verse 23, where seven women are forbidden to marry: mothers, daughters, sisters, 'ammah (aunts from a father), "khalah" (aunts from a mother), daughters of a brother, and daughters of a sister. Related to marital relations (mushaharah), there are four forbidden kinds: mother-in-law, stepdaughters, daughter-in-law, and stepmother (father's wife). A man is prohibited from marrying his father's wife, even though he has not had intercourse or there is a husband and wife relationship between the two 17 . As for what is forbidden because breastfeeding is also the same as being forbidden by the same lineage, namely breastfeeding, the mother of the nursing mother, because she is also the grandmother of a child who has been breastfed, the mother of the husband of the nursing mother (breastfeeding mother-in-law), because she is the grandmother of a child who has already been breastfed. breastfed, nurse's sister, because she is the aunt of the child being breastfed, sister of the nurse's husband, child of the nurse's offspring, both from the side of the child who is male and from the daughter (grandchildren, and their levels), because they are also breast brothers, as well as their children, and breast sisters, either from the father's or nursing mother's side or from one of the parties only 18 . At least this is a general description of women who are forbidden to marry a man forever according to the instructions contained in the Al-Qur'an and hadith.
The next category is the prohibition of marriage for a certain period (muaqqat), where several causes cause the prohibition of marriage. When the reason is no longer there, the "haram" law is replaced with "halal" 19 . The temporary marriage prohibition applies to the first case, in which two sisters (siblings) are married by a man simultaneously. The ban on 15 Abdul Rahman Ghazaly, Fiqh Munakahat (Jakarta: Kencana, 2015), pp. 7-8. 16  gathering two women in one marriage also applies to two related people, such as aunts and nephews 20 . This prohibition is stated in the hadith of the Prophet, narrated by Bukhari Muslim and Abu Hurairah. Second, a woman who is still married to another man is forbidden to marry a man. Third, women in their "iddah" period, whether divorced or divorced dead, according to Allah's word in Surah al-Baqarah verses 228 and 234. It is forbidden to marry a woman who is still someone else's wife, and it is also prohibited for her to marry a woman who is in the 'iddah' period of her marriage to another man 21 . Fourth, women who have been divorced three times. It is forbidden for a woman who has been divorced three times to remarry her ex-husband unless she has remarried to someone else until she has had sex, and then she is divorced by the last husband, and her ''iddah'' period has ended. Based on the word of Allah, Surah al-Baqarah verses 229-230. Fifth, women who are in ''ihram'', both ''umrah ihram'' and ''Hajj Ihram'', cannot be married. Sixth, polytheistic women are forbidden to marry. Polytheistic women are those who worship deities other than Allah SWT 22 . Seventh, marrying an adulteress, or marriage between a good man and a prostitute, or a good woman and an adulteress man, is not permissible except after each repents 23 .

Prohibition of Marriage in Minangkabau Customary
Tribal and village exogamy systems are used in Minangkabau culture. People from the same tribe in one Nagari cannot marry, and people from the same village cannot marry woman or men in their village, even if their ethnicity is different. According to Shafra and Yulia Rahmi, Minangkabau custom divides marriage prohibition into two types: 'perkawinan pantang' (incestuous marriage) and 'perkawinan sumbang'. 'Perkawinan pantang' is not forbidden in Islam, but the Minangkabau should avoid it 24 . According to Arisman, 'perkawinan pantang' may harm the kinship system, particularly for those who are blood-related through matrilineal lineage within one clan or tribe, even if they do not have a genealogical relationship or are not very close to each other. Same-ethnic marriage is not religiously forbidden, but only to the extent of incest prescribed by custom 25 . What has been going on for a long time, is consistent with matrilineal kinship history, and is still supported by the community 26 . The application of 'perkawinan pantang' differs from one region to another in Minangkabau. Even though people live in different regions with different headmen, most of the Luhak 50 Koto and Luhak Tanah Datar still have restrictions on same-tribal marriage. In general, the prohibition against marriage will be enforced as long as the genealogy of the same tribe can still be traced during that time. Meanwhile, in some Luhak Agam, there is already a tendency to relieve it. Same-ethnic marriages between Nagari (same tribe, but different headman) are possible. Even in one Nagari, which initially came from the same tribe, then developed due to the addition of members of the tribe with a new headman, it is permissible to marry as long as they are not of the same blood or offspring. Several areas apply stringent rules within the same Luhak. Even though they are different Nagari, they are of the same ethnic group, so they are still not allowed to marry each other 27 . 20  While 'Perkawinan Sumbang' is carried out inappropriately or not well according to the judgment of many people. So, 'Perkawinan Sumbang' is classified as an inappropriate act that is not good according to society. The perpetrator can be called a person who has no shame or is not civilized because he has committed an act that is not commendable and violates customary norms. 'Perkawinan Sumbang' also affects family self-esteem. If one of them does "Perkawinan Sumbang," the rest of the family is offended. It means that he has ignored 'raso jo pareso' (sense of examining) and 'tolerance raso' (sense of tolerance). 'Perkawinan Sumbang' can be categorized as marrying someone who has been divorced by a close friend, relative, or neighbor (other than those prohibited by religion), neighbors, marrying someone who is already engaged to someone else (outside the engagement referred to by religion), or marrying a sibling's son or daughter 28 . Socially, the prohibition of 'Perkawinan Sumbang' aims to maintain dynamics in daily social activity. People who do 'Perkawinan Sumbang' are usually the subject of conversation in society. In essence, "Perkawinan Sumbang" focuses on maintaining integrity among relatives and residents 29 . In addition, there are other types of 'Perkawinan Sumbang,' namely marriages that are not permitted by guardians and Mamak. According to Minangkabau custom, more than a guardian's permission is required to obtain permission from Mamak.
According to Minangkabau custom, the sanctions for perpetrators of "Perkawinan pantang" or "Perkawinan sumbang" do not break the marriage relationship because the community realizes that Islam does not prohibit such marriages. But both are based on the agreement of traditional leaders to be disposed of by custom, called "buang siri," meaning that the perpetrators are not brought back and forth in the community or ostracized if their mistakes have not been redeemed. Some were ordered to leave the village to avoid the embarrassment of being slandered by the community as a social sanction. They may return after the amnesty has been granted to apologize to the two clans. A traditional banquet with livestock slaughtering should be held in honor of the Nagari leaders.

Custom (adat) in Islamic Law
Abdul Wahhab Khallaf defines "urf" as something known by many people that has become their tradition, whether in words, deeds, or circumstances, to leave something (also called "adat") 30 . In discussing their position as one of the arguments for establishing syara, ushul fiqh scholars distinguished between custom and 'urf. "Custom" is done repeatedly without any rational relationship 31 , or regional customs can coexist with Islamic law. According to Badran, "urf" is anything that has been accustomed to and acknowledged by many people, either in the form of words or actions, done repeatedly so that it remains in their souls and is well accepted by their minds 32 . According to Amir Syarifuddin, the words "adat" (custom) and "urf" are "mutaradif" (synonyms). If the two words are combined in one sentence, such as "hukum itu disasarkan kepada adat dan 'urf" (law is based on custom and 'urf), it does not mean that these two words have different meanings, even though the conjunction "and" is commonly used as a word that distinguishes between the two words. Because the two words "adat" (custom) and "urf" have the same meaning, in this case, the word "urf" is a reinforcement of the word "adat" (custom) 33  According to Wanto, Imam Shafi'i is also said to hold on to "urf" in fostering the laws of his mazhab, which are "qadim" according to '"urf" of the Iraqis 34 so that al-Qaradawi says that all schools of thought equally own "urf" and anyone who researches mazhab will undoubtedly find his firmness against the "urf". According to him, "urf" is not a state of "syara" itself. In general, "urf" is intended to maintain the welfare of mankind and support the formation of laws and the interpretation of several "nash" (rulings sourced from the Quran and the Sunnah). With "urf" specifically, the pronunciation that is 'amm (general) and limited to the absolute. Because "urf" also sometimes becomes "qiyas," which is left behind. Therefore, it is legal to enter into a wholesale contract if one is used to it according to "urf", even though it is not valid according to "qiyas" because the contract is for things that are "ma'dum" (non-existent) 35 . All scholars agree that "urf is valid as one syara," that is, "urf that meets at least the criteria, namely, useful and acceptable by common sense, applies in general and equally for people in the customary environment, or among the majority of its citizens, "urf that existed (applied) at that time, not "urf that appeared later," and must not contradict and neglect existing syara or conflict with certain principles." 36 Harisuddin emphasized that "urf" must be positioned as a legal product that can genuinely produce benefits 37 . However, a fiqh expert is prohibited from giving a fatwa (decision) with 'urf that is contrary to the basis of the Shari'a, except in an emergency that requires him to decide a case according to the basis of the Shari'a, in which case the law given is justified based on the emergency and entering into rukhshah the stipulated on the path of ijtihad. Thus 'urf, which is correct or does not violate the basis of syar'i, must be considered by mujtahids and judges in deciding cases.

III. Result and Discussion
The Understanding of Marriage Prohibition of the same ethnicity (sasuku) with his ex-wife Before the researchers explains the background of the prohibition of marrying people of the same ethnicity (sasuku) to ex-wive, the researchers will first explain the meaning of "sasuku." All descendants of the grandmother are vertically considered "Sasuku." According to the mother's lineage, the tribe, or "sasuku," refers to all the grandmother's descendants. A tribal leader heads the tribal group. A marriage of the same lineage is called 'sasuku'; for example, a man from the Caniago tribe marries a woman from the Caniago tribe.
However, in Nagari Binjai, in addition to the prohibition on "sasuku," the community also recognizes the prohibition on "sasuku" with ex-wives. A widower is prohibited from marrying a woman of the same tribe as his ex-wife (widow). This marriage prohibition only occurs when a person has been married before and has been divorced. The prohibition on marrying women of the same tribe as ex-wives is similar to the prohibition on "sasuku" that society views them as still having family relations, even if a widow and a widower who are willing to marry have different ethnicity or even "datuak". Each "Nagari" has regulations that apply to all its people, varying from region to region. Minangkabau traditional saying: "lain padang lain balalang, lain lubuak lain ikan, lain nagari lain adatnyo". Likewise, the people of Nagari Binjai have customary rules and prohibitions to obey, which may differ from other areas. For example, A ( a man) from the Tanjung tribe married B (a woman) from the Caniago tribe, and then there was a divorce. Then A, who has the Tanjung ethnicity, wants to marry C (another woman with the Caniago ethnicity), so this is a marriage that is prohibited according to the custom of the Nagari Binjai because of the woman to be married is of the same ethnicity as his ex-wife, namely both Caniago 38 .
There are three forms of marriage in Minangkabau. First, marriage which is prohibited according to religion and of course, it is also prohibited in custom. Such as the prohibition of marriage due to blood ties, incest, and sexual relations (mushaharah). It is in accordance with the Minangkabau philosophy which says: "adat basandi syara', syara' basandi Kitabullah". Second, "Perkawinan Pantang" which means marriage of blood ties based on the matrilineal system, such as "perkawinan sasuku". Third, "Perkawinan sumbang"-marriages that are prohibited by customary law and are considered not good according to the community's views 39 . In this case, the prohibition against marrying a woman who has the same etnicity with an ex-wive in Nagari Binjai is categorized as a "perkawinan sumbang". It affects family self-esteem, meaning that the offender no longer values "raso jo pareso" (sense of examining) and "tenggangraso" (tolerant).

The Background of Sasuku's Marriage Prohibition with Ex-Wife
According to Datuak Labiah, the background to the prohibition on marrying a sasuku with an ex-wife in Nagari Binjai was based on an ancestral agreement made in a customary meeting. Minangkabau has customs, and customary law considers that a man who marries a woman with the same tribe as his ex-wife is a relative, or in terms of "samamak" (one mother), and the prohibition of such a marriage is also for the benefit of social life. Katokanlah aia yang kanai najis maka indak buliah digunokan untuak basuci, yang melatar belakangi syara', sedangkan kasus nikah semacam ko didasari oleh hukum adaik, kalau lah samamak kamanakan buliah lo manikah, itu ibaraik sawah indak bapamatang" (say, water that is unclean then it's not permissible used for purification, which is based on syara', while cases of marriage of this kind are based on customary law, if one mamak and niece are allowed to marry it is the same as a rice field without ripening) 40 . According to Jamal Mirdat (a community leader in Nagari Binjai), he only implements existing laws, not regulations that have been made recently. The regulation was made so there would be no social gossip. If left unchecked, an ethnic relative can eventually marry 41 .
Young Datuak says that the background to the prohibition against marrying a woman of the same ethnicity as an ex-wife is that the Minangkabau people know "raso jo pareso", which means that all actions have to be considered and checked before they are carried out. Minangkabau people are influential in guarding their feelings of ethnic relatives, which may cause conflict and damage sibling relations between them and badunsanak (those with kinships). Another reason is due to cultural factors passed down from ancient times to the present, forbidding a widower from marrying a widow with the same ethnicity as his exwife 42 . 38 Mudo, Interview. 39 Azmi, Adat dan Upacara Perkawinan Daerah Sumatera Barat, 2nd edition (Jakarta: Depdikbud RI, 1997), p. 34. 40 Asman Dt. Labiah (Ketua Kerapatan Adat Nagari), "Interview" (Binjai, 2021). 41 Jamal Mirdat (anggota masyarakat), "Interview" (Binjai, 2021). 42 Mudo, Interview.

The Impact of Marrying a Sasuku Woman with an Ex-Wife
A violation of one of the customary provisions or provisions of the Islamic religion in matters of marriage will have severe consequences for life. It may even have long-term consequences for offspring. Sanctions are punishments that every violator of the applicable provisions will receive. Violating the established law is called a deviant act and creates an imbalance in society. The goal of imposing sanctions is to deter offenders and provide lessons for those who witness them so that the same mistakes are not repeated, thereby restoring imbalances in certain societies.
To determine the sanctions for violating customary rules, violators must wait for a decision from "Datuak Kaum" made through deliberation. "Adat bajanjang naiak, batanggo turun (tradition of ascending and descending ladders) 43 which is a guideline for the Minangkabau people to follow. The goal is all decisions that have been taken can be carried out together because they result from joint deliberations. As the following Minangkabau customary philosophy"naiak dari janjang nan di bawah, turun dari tanggo nan di ateh, babilang dari raso, mangaji dari alif, kamanakan barajo ka mamak, mamak barajo ka panghulu, panghulu barajo ka mufakat,mufakat barajo ka nan bana" (going up from the bottom stairs, step down from the upper stairs, counting from the measure of taste, reciting from the letter 'Alif', nephew learns from Mamak, Mamak learns from the head, the head learns to reach a consensus, learns to the correct consensus, and what it stands alone according to to flow and etiquette).
As a customary rule, men are not allowed to marry women of the same ethnicity as their ex-wives. Men who marry "sasuku" (as it is called) with their ex-wives will face sanctions; typical sanctions for violators are social and material.

a. Social Sanctions
Old people say "babuang puluih, utang indak dapek dibayia, doso indak dapek disambah" (debts cannot be paid, and sins cannot be worshipped). It means "forever banished or ostracized." Therefore, anyone who wants to do something should think before doing it, "banyak yang lain, manga itu juo" (there are still many others, why does it have to be that too) 44 . The social sanctions that will be received by violators who carry out this kind of sasuku marriage with ex-wives are exiled within the clan or deported according to custom. "Kalau lah dibuang sapanjang adat, carilah aia yang janiah, sayak yang landai, indak mungkin yang lah kito luahkan kito makan juo baliak" (if it has been thrown away according to custom, look for clean water, gently sloping water, we can't eat what we have vomited again), meaning that the social sanctions apply forever (babuang puluih), look for another life out there 45 .
They will no longer be served and included in Minangkabau's everyday formal activities or events in Nagari Binjai. For example, if the violator has a celebration (wedding, death), all traditional stakeholders and the community will not attend. The sanction does not affect the offender's family. "Sia mandi sia basah, sia malompek sia patah, Allah mambarikan doso ka urang nan babuek doso, pemerintah manjatuahkan hukuman kapado nan basalah" (who bathes gets wet, who jumps breaks, Allah gives sins to those who commit sins, the government sentences the guilty). So according to customary law, "buruak sabatang is chewed, buruak saumpun is diungkah, mancaliak levels" (it's wrong to cut a piece of wood, it's terrible to take a lump of it, depending on the amount). Holding a sasuku marriage is considered as "buruak saumpun "46 .
According to Nuri, social sanctions are the most severe sanctions. Being ostracized is a sign that the person concerned has violated tradition 47 . However, according to Sansi, the sanctions given to violators do not extend to marriage annulment because the community is aware that such marriages are not prohibited in Islam 48 . Hilman Hadikusuma says communities following customary law do not recognize marriage annulment institutions. In Minangkabau, if a marriage is considered immoral or contrary to custom, an annulment of the marriage is not submitted, but a divorce is proposed 49 . The social sanctions the perpetrators receive are only temporary until the person concerned redeems them based on customary deliberations in the form of an apology or a certain fine. Meanwhile, whether a marriage is legal is still based on Islamic law 50 .

b. Material Sanctions
The material sanction for perpetrators who carry out marriage "sasuku" with their ex-wives is that they will no longer receive the proceeds from "tanah pusako." "Sanksi materil harusnyo maikuik" (material sanctions must follow), violators will no longer be able to get a share of the property. Their children will get the property. The mother can't take the house, land, and rice fields; their children will get them because these sanctions are only imposed on husbands and wives who violate the customary rules, not on children or their families. If they do not have children, the heirs will take over 51 . Regarding marrying sasuku with ex-wives, violators have no more opportunities to return to their people by apologizing or slaughtering a cow as fines of customary law in general 52 .

Perspective of Islamic Law Against the Prohibition of Marrying Sasuku Women with Ex-Wives
Every region in Minangkabau cannot be separated from three elements of leadership: "penghulu" (the chief), the "alim ulama" (scholars), and the "cadiak pandai" (the intellectual people). These three elements work together to regulate a better life, both individually and in society. The three aspects of leadership are called "tungku tigo sajarangan." The existence of these three elements is known as "tali tigo sapilin" (three bundles of rope), namely, religion, custom, and law (government) 53 .
The "Penghulu" (the chief) is a person who has a deep mind and good communication skills (deep sense, soft speech). This means that the person who will become "Penghulu" must be chosen by his people who are mature enough. A "Penghulu" must have good manners, courtesy, hospitality, humility, and other good behavior. Because "Penghulu" will be a role model for his people, he leads 54 . His task is to solve problems that may arise in people's lives. If the issue concerns law and justice, then he must decide it. For example, "maelo rambuik dalam tapuang atau mamalu ula dalam bania," which means that the chief's 46 Ibid. 47  task is only to resolve the issue wisely and clear up the murky things and solve the tangled ones, as it is known as "manjaniahkan nan karuah dan manyalasaikan nan kusuik." 55 . The Minangkabau people, especially in Nagari Binjai, have a marriage system that is slightly different from most other areas in Indonesia. The Minangkabau people's marriage system adheres to exogamy, which requires a person to find a mate outside the social environment, among relatives, or in another place 56 . The Minangkabau people's philosophy of life is "adat basandi syarak, syarak basandi Kitabullah; syarak mangato dan adat mamakai" (customs based on syarak, syarak based on the Al-Qur'an, syarak saying and custom wearing). That is, custom and tradition must be under sharia based on the Al-Qur'an, and what applies in the life of the Minangkabau people is sharia law 57 . According to Naseh, the application of sharia law means that the Minangkabau people no longer practice customs that are not following Islamic law 58 . The process towards "adat basandi syarak, syarak basandi Kitabullah; syarak mangato and adat mamakai" can be seen from three things. First, customary rules that do not align with or conflict with Islamic law (syarak) must be eliminated or replaced with Islamic law (syarak). Second, traditional practices that do not conflict with syara' are still used, but refined with syara'. Third, syara' cannot replace regular rules but is strengthened for several reasons 59 .
No written regulation in Islamic law governs the prohibition against "sasuku" Marriage with ex-wives; this prohibition only applies to the community or indigenous people, not to customary law. Because the prohibition was enacted and enforced by traditional stakeholders, Marriage is a sunnah, and every creature is subject to Allah SWT's laws. Assume it is against Allah SWT's rules. In that case, he no longer applies Islamic law because it is impossible for society to influence the essence of worship that has been regulated by religion 60 .
Marriage provisions in the Nagari Binjai community, Tigo Nagari District, Pasaman Regency, West Sumatra Province, state conclusively that families who want to marry their family members must be from a tribe not prohibited by Nagari Binjai customary rules. There are two legal requirements in Islamic law for a marriage: the prospective bride is "halal" to be married by a man who wants to make her his wife (the woman is not an illegitimate bride-tobe, either because it is illegal to marry temporarily or permanently); and witnesses attend the marriage contract. In conclusion, there are no explicit rules in Islamic law that say marriages must be between people of different ethnicities with ex-wives.
The prohibition of marrying "sasuku" with ex-wives is to maintain social dynamics, maintain the rules or oaths agreed upon by the ancestors, and maintain integrity among relatives and fellow citizens to achieve social benefits in social life in Minangkabau, especially in Nagari Binjai, Tigo Nagari District, Pasaman Regency, West Sumatra Province. The ushul fiqh rule mentions "dar al-mafsid muqaddamah ala jalb al-mashalih" 61 (leaving all "mafsada" should take precedence over benefiting). This rule is the basis to strengthen the prohibition on marrying sasuku with ex-wives because it can prevent disharmony in social relations.