Ja'far bin Rabi'ya bin Shrhbyl جعفر بن ربيعة بن شرحبيل · The Book of Marriage

"O Messenger of Allah, marry my sister, the daughter of Abu Sufyan." She said: "The Messenger of Allah said: 'Would you like that?' I said: 'Yes; I do not have you all to myself and I would like to share this goodness with my sister.' The Prophet said: 'Your sister is not permissible for me (to marry).' I said: 'By Allah, O Messenger of Allah, we have been saying that you want to marry Durrah bint Abi Salamah.' He said:…

"Aishah said: 'The Messenger of Allah entered upon me and there was a man sitting with me. He got upset about that, and I saw the anger in his face.' I said: "O Messenger of Allah, he is my brother through breast-feeding." He said: "Be careful who you count as your brothers" --or: "be careful who you count as your brothers through breast-feeding"-- "for the breast-feeding (which makes marriage prohibited) is from hunger."