Chapter 57: One-fifth of Booty to the Cause of Allah (Khumus)
Narrated 'Amra bint 'Abdur-Rahman: 'Aisha, the wife of the Prophet (ﷺ) told her that once Allah' s Messenger (ﷺ) was with her and she heard
somebody asking permission to enter Hafsa' s house. She said, "O Allah' s Messenger (ﷺ)! This man is asking
permission to enter your house." Allah' s Messenger (ﷺ) replied, "I think he is so-and-so (meaning the foster
uncle of Hafsa). What is rendered illegal because of blood relations, is also rendered illegal because of
the corresponding foster-relations."
Sahih al-Bukhari 3105