and maternal uncles and aunts through breastfeeding. All of this is agreed upon by the Muslims. Thus, the marriage prohibition arising from breastfeeding extends through both parents and through the child.

As for the breastfed child’s father, mother and grandmothers, and brothers and sisters by blood, all of these are unrelated to the nursing woman and her relatives, by agreement of the scholars. His brother by blood may therefore marry his sister through breastfeeding. All the breastfed child’s brothers may marry whichever of the nursing woman’s daughters they wish, including the daughter breastfed alongside the child as well as the others. The breastfed child himself, however, may not marry any of the nursing woman’s children, whether born before or after the breastfeeding, by agreement of the scholars.

Many people make a mistake in this matter: they fail to distinguish between the breastfed child’s siblings by blood, who are unrelated to the woman, and the nursing woman’s children, who are his siblings through breastfeeding. They treat them all as one category, but this is not so. Rather, members of the former group may marry members of the latter. The breastfed child himself, however, may not marry any of the nursing woman’s children.

If a boy and a girl are each breastfed by the other’s mother—the boy by the girl’s mother and the girl by the boy’s mother—and none of her siblings is breastfed by the other child’s mother, each child is forbidden to marry any of his or her nursing mother’s children, whether born before or after the breastfeeding. A brother by blood of either child, however, is not forbidden to marry the other child’s sister through breastfeeding.