Ruling 2499 — Breastfeeding

A man cannot marry women who have become his wife’s nieces through breastfeeding without his wife’s permission. Furthermore, if a man sodomises a boy who is not of the age of legal responsibility (bāligh), he cannot marry the boy’s nursing daughter, sister, mother, or grandmother, i.e. those who are his daughter, sister, mother, or grandmother through breastfeeding. The same applies, based on obligatory precaution, if the sodomiser is not bāligh or the sodomised individual is bāligh.