Another example: A child nursed from a woman named Hind alongside her daughter Aisha. Hind had daughters before him; they are his foster sisters, because they are among the descendants of the nursing woman, Hind. He is likewise a foster brother to the daughters born after him, because they too are among the descendants of the nursing woman.

A second example: A man nursed from a woman who had a son named Ali, and Ali had a daughter. May the nursling marry Ali’s daughter? No, he may not, because she is among the descendants of the nursing woman; and, with respect to the nursing woman, breastfeeding affects her ascendants, descendants, and collateral relatives.

A third example: A man nursed from the wife of Zayd, and Zayd had another wife who had daughters. He may not marry them, because they are among the descendants of the man to whom the milk is attributed.

Issue: Does breastfeeding render unlawful the same relations that marriage relations render unlawful? The scholars differed on this. The four imams and the majority of the scholars held that breastfeeding renders unlawful the same relations that marriage relations render unlawful. Accordingly, your wife’s foster mother is forbidden to you, just as your wife’s mother by blood is forbidden to you, for a wife’s mother by blood is forbidden by explicit text and scholarly consensus, as Allah Most High says: “And your wives’ mothers.”

Likewise, your wife’s foster daughter—for example, if you have a wife who nursed a girl from a previous husband—is, according to the majority, forbidden to you, because she is your wife’s foster daughter and is therefore like your wife’s daughter by blood. Likewise, if a woman’s husband has a foster father, he is forbidden to her—according to the majority—just as her husband’s father by blood is forbidden to her. And if her husband has a foster son—that is, he did not nurse from her, but nursed from another wife—then he