Does prohibition spread between the man whose semen resulted in the milk and the wet nurse if the milk resulted from an illicit relationship (Zina) or denial of paternity (Li'an)?
General Chapter
Al-Mughni
Book of Fosterage (Breastfeeding)
Primary text
Al-Kharqi stipulated that for prohibition to spread between the nursed child and the man whose semen resulted in the milk (through sexual intercourse), the intercourse must have been in a valid marriage, legal ownership (milk Yamin), or a similar ambiguity. Thus, the milk of a fornicator (Zani) or one who denies paternity via Li'an does not spread the prohibition between them, according to the understood meaning of Al-Kharqi's statement. This is the view of Abu Abdullah Ibn Hamid and the madhab of Al-Shafi'i.
Supporting text
Abu Bakr Abd Al-Aziz holds that prohibition spreads between them because it is a matter that spreads prohibition, thus whether it is permissible or forbidden is equivalent, similar to sexual intercourse which establishes lineage and progeny, and the progeny spreads prohibition to the father, similarly the milk should. This is because the nursing spreads prohibition to the wet nurse, so it spreads it to the man, as in the established scenario. The first position argues that the prohibition between them is contingent upon the prohibition of paternity; since paternity is not established, the derivative thereof is not established. It differs from the prohibition due to Zina's daughter because she is truly from his semen, unlike this issue. It also differs from the prohibition by affinity (Musaharah), where prohibition does not depend on establishing lineage, e.g., the mother and daughter of the wife are prohibited without lineage. The prohibition of nursing is built upon lineage, evidenced by the saying: 'Prohibit by nursing what is prohibited by lineage.' The nursed child is prohibited to the wet nurse and attributed to her by all scholars, as are all her children and relatives who would be prohibited to her children.