Musnad Ahmad 1153:76

Sufyan narrated to us, from al-Zuhri, from ‘Urwah, from ‘Aishah: My paternal uncle came after the hijab had been imposed, so I refused to give him permission [to enter]. I asked him [the Prophet], and he said: "Give him permission, for he is your paternal uncle." I said: "It was the woman who nursed me, and the man did not nurse me." He said: "May your right hand be covered in dust, give him permission, for he is indeed your paternal uncle."