Aflah, the brother of Abi Al-Quais, asked permission to visit me after the order of Al-Hijab was revealed. I said, "I will not permit him unless I take permission of the Prophet about him for it was not the brother of Abi Al-Qu'ais but the wife of Abi Al-Qu'ais that nursed me." The Prophet entered upon me, and I said to him, "O Allah's Apostle! Allah, the brother of Abi Al-Qu'ais asked permission to visit me but I refused to permit him unless I took your permission." The Prophet ﷺ said, "What stopped you from permitting him? He is your uncle." I said, "O Allah's Apostle! The man was not the person who had nursed me, but the woman, the wife of Abi Al-Qu'ais had nursed me." He said, "Admit him, for he is your uncle. Taribat Yaminuki (may your right hand be saved)" 'Urwa, the sub-narrator added: For that 'Aisha used to say, "Consider those things which are illegal because of blood relations as illegal because of the corresponding foster relations."
Sahih al-Bukhari, Vol. 6, Book of Prophetic Commentary on the Qur'an, Hadith 319
Sahih al-Bukhari, Book of Prophetic Commentary on the Qur'an, Hadith 319