Ibn Ishaq محمد بن إسحاق بن يسار‎ · The Chapters on Marriage

“Once of the things that Allah revealed in the the Qur'an and then abrogated was that nothing makes marriage prohibited except ten breastfeedings or five well-known (breastfeedings).”

that the Prophet entered upon her and there was a man with her. He said: “Who is this? She said: “This is my brother.” He said: “Look at whom you allow to enter upon you, because the breastfeeding (that makes a person Mahram) is that which satisfies hunger.”

"We went out with the Messenger of Allah on the Farewell pilgrimage, and they said : 'O Messenger of Allah, (ﷺ) celibacy has become too difficult for us'. He said : 'Then make temporary marriages with these women'. So we went to them, but they insisted on setting a fixed time between us and them. They mentioned that to the Prophet and he said : 'Set a fixed time between you and them.' So I went out with a cousin…

"I heard the Messenger of Allah say: 'I wanted to forbid intercourse with a nursing mother, but then (I saw that) the Persians and the Romans do this, and it does not kill their children.' And I heard him say/when he was asked about coitus interruptus: 'It is the disguised form of b.rryirg children alive."