7. Ali ibn Ibrahim has narrated from his father from and Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from ibn abu Najran from Muhammad ibn ‘Ubayd al-Hamadaniy who has said the following:

“Al-Rida’ , once asked me, ‘What do your people say about breastfeeding?’ I replied, They called it the milk of the ‘impregnating agent’ (husband) until a Hadith from you came to them that said, “Because of breastfeeding whoever is unlawful for marriage, as being a relative, becomes unlawful” then they returned to your words.’ He (the narrator) has said that he (the Imam) said, ‘It is because ’Amir al-Mu’minin, (the Caliph, Mamun) asked me last night about it and said, “Explain to me the milk of Fahl (‘impregnating agent’, husband) and I do not like words.” Then he said to me, “Bear with me as you are, so I can ask you about it which is what you have said about the case of a man who has several mothers of his children and one of them breastfeeds a stranger boy. Are all of the children of this man from all of the mothers of his children not lawful for marriage to this boy?” I said, “Yes they are unlawful for him.’” He (the narrator) has said, ‘Abu al-Hassan , then said, ‘How is it that breastfeeding because of the milk of the ‘impregnating agent’ has an unlawfulness affect but not because of the breastfeeding of the mothers even though breastfeeding is by the mothers; still the milk of the ‘impregnating agent’ (husband), also brings unlawfulness.’”