Sahih al-Bukhari 2646
Witnesses
To give witness concerning lineage, foster suckling relations and dead persons
Narrated `Amra bint `Abdur-Rahman: That `Aisha the wife of the Prophet (ﷺ) told her uncle that once, while the Prophet (ﷺ) was in her house, she heard a man asking Hafsa's permission to enter her house. `Aisha said, "I said, 'O Allah's Messenger (ﷺ) ! I think the man is Hafsa's foster uncle.' " `Aisha added, "O Allah's Messenger (ﷺ) ! There is a man asking the permission to enter your house." Allah's Messenger (ﷺ) replied, "I think the man is Hafsa's foster uncle." `Aisha said, "If so-and-so were living (i.e. her foster uncle) would he be allowed to visit me?" Allah's Messenger (ﷺ) said, "Yes, he would, as the foster relations are treated like blood relations (in marital affairs).