and those of her husband, whether through blood or breastfeeding. The siblings of one may marry the siblings of the other; indeed, a person’s biological father may marry that person’s sister through breastfeeding. As for the wet nurse’s children, none may marry the breastfed person or his children. Nor may the breastfed person marry any children of his brothers or sisters, whether the sibling relationship is through blood or breastfeeding, since he would be their paternal or maternal uncle. All of this is agreed upon among the scholars.

Regarding the breastfeeding that establishes a marriage prohibition, there are three well-known opinions, all three reported from Ahmad.

The first is that breastfeeding establishes this prohibition whether the amount is great or small. This is the position of Mālik and Abū Hanīfa, based on the Quran’s unrestricted wording.

The second is that one or two breastfeedings do not establish the prohibition, but more than that does. This is the position of a group of scholars, based on the Prophet’s statement, blessings and peace be upon him, in an authentic hadith:

“One or two breastfeedings do not establish a marriage prohibition.”

Another version reads, “one suck or two,” and another, “one suckling or two.” Thus, he excluded these two amounts from establishing the prohibition, while all other amounts remain covered by the general wording and its implied meaning.

The third is that nothing less than five breastfeedings establishes the prohibition. This is al-Shāfiʿī’s position and the apparent position of Ahmad’s school, based on two authentic hadiths. The first is the hadith of ʿĀʾisha:

“Among what was revealed of the Quran were ten specified breastfeedings, which were then abrogated by five specified breastfeedings. The Messenger of Allah, blessings and peace be upon him, passed away while the matter remained thus.”

The other is his instruction, blessings and peace be upon him, to the wife of Abū Hudhayfa ibn ʿUtba ibn Rabīʿa to breastfeed Sālim, the freedman of Abū Hudhayfa ibn ʿUtba ibn Rabīʿa, five times, so that he would thereby become her mahram—a man permanently forbidden to her in marriage.