Musnad Ahmad 1153:1602

Yahya narrated to us, Hisham narrated to us, he said: My father narrated to me, from Aisha, she said: My paternal uncle through breastfeeding came to me seeking permission to enter upon me after the hijab had been imposed. I said: I will not give you permission until I ask the Messenger of Allah, peace and blessings of Allah be upon him. I mentioned that to the Messenger of Allah, peace and blessings of Allah be upon him, and he said: "Let your paternal uncle enter upon you." I said: It was the woman who breastfed me, and the man did not breastfeed me. The Messenger of Allah, peace and blessings of Allah be upon him, said: "He is your paternal uncle, so let him enter upon you."