blood kinship.”

The second wording is:

“The same marriages are forbidden through breastfeeding as through birth.”

Some later jurists have excluded two cases from this general rule, while others have excluded more. This is mistaken, for nothing needs to be excluded from the hadith. We explain this as follows:

If an infant receives five breastfeedings from a woman within the first two years of life, she becomes his mother, and her husband, through whose intercourse the milk was produced, becomes his father. Thus, he becomes the son of each of them through breastfeeding. All the woman’s children, whether by this man or another, and all the man’s children, whether by her or another woman, consequently become his siblings, regardless of whether they were born before or after the breastfeeding. The imams agree on this.

Since their children are his siblings, their grandchildren are his siblings’ children. He therefore may not marry any of their children or grandchildren, because they are either his siblings or his siblings’ children, and such marriages are forbidden through birth.

The woman’s brothers and sisters are his maternal uncles and aunts through breastfeeding, and her father and mother are his grandparents through breastfeeding. He therefore may not marry any of her brothers or sisters. The man’s siblings are his paternal uncles and aunts, and the man’s father and mothers are his grandfathers and grandmothers. He may therefore marry neither his paternal uncles and aunts nor his grandfathers and grandmothers. He may, however, marry the children of his paternal uncles and aunts. For all a man’s relatives are forbidden to him [except] the children of his paternal uncles and aunts and the children of his maternal uncles and aunts, as Allah states in His words: