and her maternal aunt, for the Messenger of Allah ﷺ said, “Do not marry a woman together with her paternal aunt, nor a woman together with her maternal aunt.” Agreed upon. He ﷺ also explained the wisdom behind this ruling: “If you do that, you will sever your family ties,” for co-wives are prone to jealousy, and if one of them is related to the other, estrangement between relatives is almost certain. Once a woman is divorced and her waiting period has ended,, however, her sister, her paternal aunt, and her maternal aunt all become lawful for the man to marry, because the underlying concern is no longer present.

Likewise, a man may not be married to more than four women at one time. Allah the Exalted says, “Marry such women as seem good to you—two, three, or four” (Q 4:3). When someone embraced Islam while having more than four wives, the Prophet ﷺ instructed him to release any wives beyond the limit of four.

Second category: women who are forbidden only because of a circumstance that will pass.

It is unlawful to marry a woman who is still observing her ʿidda for another man, for Allah says, “Do not resolve upon the marriage contract until the prescribed term has reached its end” (Q 2:235). The wisdom is that she might be pregnant, which would result in mixed lineages and confused parentage.

It is also forbidden to marry a woman known to be an adulteress until she has repented and her waiting period is complete, as the Almighty says, “The adulteress—no one shall marry her except an adulterer or an idolater; that has been prohibited to the believers” (Q 24:3).