‘I do not have you to myself, and my sister is the one most entitled to share this good with me.’ He said, ‘She is not lawful for me.’ He was then told, ‘We hear that you intend to marry Durra, the daughter of Abū Salama.’ He replied, ‘Even if she were not my stepdaughter under my care, she would still not be lawful for me, for she is the daughter of my brother through breastfeeding. Thuwayba, Abū Lahab’s slave woman, nursed both me and her father, Abū Salama. So do not offer me your daughters or your sisters in marriage.’” This is agreed upon among the scholars.

The “governing rule” here is that a man may not be married simultaneously to any two women whose blood relationship would preclude their marriage to one another if one of them were male. Kinship that precludes marriage entails “four rulings”: two are agreed upon, and two are disputed.

Such relatives may neither enter into marriage with one another nor have sexual intercourse. Thus, a man may neither marry a female relative whom he is permanently forbidden to marry nor take her as a concubine. This is agreed upon. Indeed, in this regard, breastfeeding prohibits what blood relationship prohibits: such a woman is lawful to him neither through marriage nor through ownership as a slave.

Nor may he be married simultaneously to two women related in this way. He may not combine two sisters in marriage, or a woman and her paternal aunt, or a woman and her maternal aunt. This, too, is agreed upon.

He may own both women as slaves, but he may not take both as concubines. Those who prohibit combining them in marriage also prohibit combining them as concubines. Thus, he may not take two sisters as concubines, or a slave woman and her paternal aunt, or a slave woman and her maternal aunt. This is the position on which the majority of the Companions ultimately settled, and it is the view of most scholars.

They agree that a man may not take as a concubine a woman forbidden to him through blood relationship or breastfeeding. Their disagreement concerned only combining two women. Some of the Companions therefore withheld judgment on this matter, saying: “One verse made both lawful, while both were made unlawful by