Muwatta 1763

Malik transmits from Hisham ibn Urwa, from his father, from Aisha, mother of the believers, that she said: my paternal uncle through fosterage came asking to enter, and I refused until I asked the Messenger. The Messenger came and I asked him. He said: he is your uncle, so let him in. She said: Messenger of God, it was a woman who nursed me, not a man. He said: he is your uncle, so let him enter upon you. Aisha said this was after the veil had been imposed on us. She also said: what fosterage forbids, birth forbids too. ¹

Belongs to the Muwatta, Book of Fosterage. Source: the Muwatta. Mentions Malik ibn Anas, Hisham ibn Urwa, Urwa ibn al-Zubayr, Aisha bint Abi Bakr. Built on in the chapters on fosterage.