10. Ibn Mahbub has narrated from Hisham ibn Salim from ‘Ammar al-Sabatiy who has said the following: “This is concerning my question before abu ‘ Abd Allah عليه السلام, about the case of a boy who is breastfed by a woman; if it is lawful for him to marry her sister because of breastfeeding who is from her father’s side. He (the narrator) has said that he (the Imam) said, ’No, because all are breastfed from the milk of one “impregnating agent” (husband).’ He asked, ‘Can he marry her sister because of breastfeeding who is from her mother’s side?’ He (the narrator) has said, that he (the Imam) said, ‘It is not unlawful because in the case of his sister who is breastfed, her “impregnating agent” (husband) is different from the one that has breastfed the boy so the two “impregnating agents” are different, thus it is not unlawful.’”