Can You Marry a Woman and Her Aunt?
Question

Please guide me in the light of Surah An-Nisa verse number 23 and 24. The husband wants to marry his wife’s sister’s daughter (means wife niece). Can he marry his wife’s niece and have at the same time both women in Nikkah?
Praise be to Allah.Islamic Marriage Restrictions on Close Relatives
It is not permissible for a man to be married to two sisters at the same time or to a woman and her paternal or maternal aunt at the same time, because Allah says (interpretation of the meaning):
{Forbidden to you (for marriage) are: your mothers, your daughters, your sisters, your father`s sisters, your mother`s sisters, your brother`s daughters, your sister`s daughters, your foster mothers who gave you suck, your foster milk suckling sisters, your wives` mothers, your stepdaughters under your guardianship, born of your wives to whom you have gone in — but there is no sin on you if you have not gone in them (to marry their daughters), — the wives of your sons who (spring) from your own loins, and two sisters in wedlock at the same time, except for what has already passed; verily, Allah is Oft-Forgiving, Most Merciful.} [An-Nisa` 4:23]
Shaykh `Abd Al-Rahman As-Sa`di (may Allah have mercy on him) said in his Tafsir (1/173): These verses refer to those who are prohibited in marriage because of blood ties, those who are prohibited because of breastfeeding, those who are prohibited because of ties through marriage , those who are haram because it is not permitted to be married to them and another woman at the same time, and women who are permissible in marriage.
With regard to those who are prohibited because it is not permitted to be married to them and another woman at the same time, Allah mentions being married to two sisters at the same time and describes it as prohibited.
And the Prophet (blessings and peace of Allah be upon him) forbade being married to a woman and her paternal or maternal aunt at the same time. So if we take a pair of women who are related to one another, if we imagine that one of them is male and the other is female, if it would be prohibited for them to get married, then it is prohibited for them to be co-wives. That is because of the severing of ties between relatives which would result from that. (End quote)
Hadith on Marriage with Paternal or Maternal Aunts
Al-Bukhari (5109) and Muslim (1408) narrated from Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (blessings and peace of Allah be upon him) said: “One should not be married to a woman and her paternal aunt, or a woman and her maternal aunt, at the same time.”
Ibn Qudamah (may Allah have mercy on him) said, explaining the women who are forbidden in marriage: “married to a woman and her paternal aunt, or a woman and her maternal aunt, at the same time” – Ibn Al-Mundhir said: The scholars unanimously agreed on this matter and there is no difference of opinion concerning it, praise be to Allah, except that some of the innovators whose difference of opinion does not count, namely the Rafidis and Khawarij, do not regard that as forbidden and they do not follow the Sunnah that is proven from the Messenger of Allah (blessings and peace of Allah be upon him), as it says in the Hadith of Abu Hurayrah (quoted above).
The Wisdom behind the Prohibition
The reason for the prohibition on being married to two sisters at the same time is that it would cause enmity among relatives and lead to severing the sacred ties of kinship, and this reason is also applicable in the case of marriage to a woman and her maternal or paternal aunt at the same time.
If they quote as evidence the general meaning of the words of Allah (interpretation of the meaning): {All others are lawful,} [An-Nisa` 4:24], then the report we have narrated makes exceptions from that. (End quote from Al-Mughni, 7/89)
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And Allah knows best.