between the two cases: the mother and daughter of the woman with whom intercourse occurred under a mistaken assumption of legality are among the man’s mahrams, because he had intercourse believing it to be lawful.

For example, a man marries a woman, then later discovers that she is his foster sister. His intercourse with her was under a mistaken assumption of legality, because he was unaware of its prohibition at the time of intercourse. Therefore, the mother of this wife is forbidden to him and is among his mahrams, because when he had intercourse with the woman he married, he believed that she was lawful for him.

Issue: Is a woman who is temporarily forbidden to him among his mahrams, such as his wife’s sister?

Answer: She is not among his mahrams, because she is not permanently forbidden to him. A wife’s sister is not forbidden to her husband in herself; rather, what is forbidden is marrying both sisters at the same time. Hence Allah says: “And that you marry two sisters together.” [al-Nisa’ 4:23] The Prophet, peace and blessings be upon him, said: “A woman and her paternal aunt must not be married to the same man, nor a woman and her maternal aunt.” (1)

The following conditions are required for a mahram:

First: He must be a Muslim. If he is a disbeliever, he is not a mahram. The apparent meaning of the jurists’ statements is that he is not a mahram whether the woman shares his religion or differs from him. Accordingly, a disbelieving father is not a mahram to his disbelieving daughter, and a father who does not pray is not a mahram to his daughter who prays, because it is a condition of a mahram that he be Muslim; one who is not Muslim is not a mahram.