Ibn 'Abbas further said, "Seven types of marriages are unlawful because of blood relations, and seven because of marriage relations." Then Ibn 'Abbas recited the Verse: "Forbidden for you (for marriages) are your mothers..." (4:23). 'Abdullah bin Ja'far married the daughter and wife of 'Ali at the same time (they were step-daughter and mother). Ibn Sirin said, "There is no harm in that." But Al-Hasan Al-Basri disapproved of it at first, but then said that there was no harm in it. Al-Hasan bin Al-Hasan bin 'Ali married two of his cousins in one night. Ja'far bin Zaid disapproved of that because of it would bring hatred (between the two cousins), but it is not unlawful, as Allah said, "Lawful to you are all others [beyond those (mentioned)] . (4:24).Ibn 'Abbas said: "If somebody commits illegal sexual intercourse with his wife's sister, his wife does not become unlawful for him."And narrated Abu Ja'far, "If a person commits homosexuality with a boy, then the mother of that boy is unlawful for him to marry."Narrated Ibn 'Abbas, "If one commits illegal sexual intercourse with his mother in law, then his married relation to his wife does not become unlawful." Abu Nasr reported to have said that Ibn 'Abbas in the above case, regarded his marital relation to his wife unlawful, but Abu Nasr is not known well for hearing Hadith from Ibn 'Abbas.Imran bin Hussain, Jabir b. Zaid, Al-Hasan and some other Iraqi's, are reported to have judged that his marital relations to his wife would be unlawful. In the above case Abu Hurairah said, "The marital relation to one's wife does not become unlawful except if one as had sexual intercourse (with her mother)." Ibn Al-Musaiyab, 'Urwa, and Az-Zuhri allows such person to keep his wife. 'Ali said, "His marital relations to his wife does not become unlawful."

Narrated `Abdullah bin Abi Mulaika: `Uqba bin Al-Harith said that he had married the daughter of Abi Ihab bin `Aziz. Later on a woman came to him and said, "I have suckled (nursed) `Uqba and the woman whom he married (his wife) at my breast." `Uqba said to her, "Neither I knew that you have suckled (nursed) me nor did you tell me." Then he rode over to see Allah's Apostle at Medina, and asked him about it. Allah's Apostle said, "How can you keep her as a wife when it has been said (that she is your foster-sister)?" Then `Uqba divorced her, and she married another man.

Narrated `Abdullah bin Abu Mulaika: `Uqba bin Al-Harith said that a black woman came and claimed that she had suckled both of them (i.e. `Uqba and his wife). So, he mentioned that to the Prophet who turned his face from him and smiled and said, "How (can you keep your wife), and it was said (that both of you were suckled by the same woman)?" His wife was the daughter of Abu Ihab-al-Tamimi.

Narrated `Abdullah bin Abu Mulaika from `Uqba bin Al-Harith: `Uqba married the daughter of Abu Ihab bin `Aziz, and then a woman came and said, "I suckled `Uqba and his wife." `Uqba said to her, "I do not know that you have suckled me, and you did not inform me." He then sent someone to the house of Abu Ihab to inquire about that but they did not know that she had suckled their daughter. Then `Uqba went to the Prophet in Medina and asked him about it. The Prophet said to him, "How (can you keep your wife) after it has been said (that both of you were suckled by the same woman)?" So, he divorced her and she was married to another (husband).

Narrated `Uqba bin Al-Harith: That he had married Um Yahya bint Abu Ihab. He said. "A black slave-lady came and said, 'I suckled you both.' I then mentioned that to the Prophet who turned his face aside." `Uqba further said, "I went to the other side and told the Prophet about it. He said, 'How can you (keep her as your wife) when the lady has said that she suckled both of you (i.e. you and your wife?)" So, the Prophet ordered him to divorce her.

Narrated `Uqba bin Al-Harith: I married a woman and later on a woman came and said, "I suckled you both." So, I went to the Prophet (to ask him about it). He said, "How can you (keep her as a wife) when it has been said (that you were foster brother and sister)? Leave (divorce) her.