I recently watched a lecture and part of it related a hadith, not word for word but basically ali asked the prophet peace be upon him to consider marrying the daughter of Hamza and he (saw) said that she is not permissible for him to marry because he (saw) and Hamza were foster brothers. I am just wondering if my brother married a woman who has a daughter she will not be permissible for me to marry? If I have understood this wrong can you please clarify.
Wa Alaikum Assalaam,
الجواب و بالله التوفيق
Hamza (R.A) was the foster brother of the Prophet (S.A.S) and so, his daughter was a foster niece to the Prophet (S.A.S). In Islam, ‘fosterage’ brings about the same prohibition as one’s blood relatives, since both are treated in the same manner. About this, the Prophet (S.A.S) said, ‘Fosterage makes haram (unlawful) what blood relations make unlawful.’ (Bukhari)
From this, it is known that the relationships that are unlawful through blood and lineage will also be unlawful through fosterage. In the case of Hamza’s daughter, she was the foster niece of the Prophet (S.A.S). This means that she had the same status of being a real blood related niece, and so, it was not permissible for the Prophet (S.A.S) to marry her.
In the case which you have asked about, it will be permissible for you to marry the daughter of the woman with whom your brother married (that is, the woman had a daughter from a previous marriage before marrying your brother).
This girl is not the daughter of your brother, and so, she is not blood related to you or your brother. She is the daughter of the woman with whom your brother married, and there is also no blood or foster relations between you and this woman. Hence, it will be permissible for you to marry this girl.
And Allah Knows Best.
Mufti Waseem Khan.
This answer was collected from DarulUloomTT.net, which is operated under the supervision of Mufti Waseem Khan from Darul Uloom Trinidad and Tobago.