matters; for one must first form a conceptual understanding, and only then determine the ruling. Yet the Quran and the sunnah are easier.

If someone were to ask: Is it permissible to be married simultaneously to a man’s wife and his daughter from another wife? Suppose a man dies, leaving behind his wife and a daughter from another wife, and another man marries both of them, being married to them at the same time: this is permissible. Even though, if we were to suppose one of them male, he could not marry the other, scholars say that in this case he could not marry her because of marital affinity; therefore, simultaneous marriage to them is permitted. Hence, when we refer back to the Book and the sunnah regarding this particular issue—and other issues as well—we find that the Quranic and Prophetic wording is clearer.

A man’s wife and his daughter from another wife are not two sisters, nor an aunt and her niece through a brother, nor an aunt and her niece through a sister; therefore, it is permissible to marry them simultaneously. This question is frequently asked: How can one be married simultaneously to a man’s wife and his daughter from another wife?

We say: Yes, because Allah has made the matter clear, saying:

“And lawful to you are all beyond these.” [al-Nisa 4:24]

Is simultaneous marriage to two foster sisters, or to a woman and her foster paternal aunt or foster maternal aunt, forbidden or not?

The correct view, without doubt, is that it is forbidden to be married to them simultaneously. This is the view of the majority of scholars, and there is no difficulty in it, because its evidence is clear: “Fosterage makes unlawful what blood relationship makes unlawful.” (1) Just as simultaneous marriage to these two women is forbidden on account of blood relationship, it is likewise forbidden on account of fosterage.