Musnad Ahmad 1153:1805

Isma'il narrated to us, he said: 'Abbad bin Mansur narrated to us, he said: I said to Al-Qasim bin Muhammad: "The wife of my father breastfed a young girl from among the people with the milk of my brother. Do you see that I may marry her?" He said: "No, your father is her father." Then he narrated the hadith of Abu al-Qu'ays, and he said: "Indeed, Abu al-Qu'ays came to 'Aishah seeking permission to enter upon her, but she did not grant him permission. When the Messenger of Allah (ﷺ) came, she said: 'O Messenger of Allah, Abu al-Qu'ays came seeking permission to enter upon me, but I did not grant him permission.' He said: 'He is your paternal uncle, so let him enter upon you.' I said: 'The woman breastfed me, but the man did not breastfeed me.' He said: 'He is your paternal uncle, so let him enter upon you.'"