Sunan an-Nasa'i 120

It was narrated that Usamah bin Zaid said:"The Messenger of Allah (ﷺ) and Bilal entered Al-Aswaf [1] and he went to relieve himself and then came out." Usamah said: "I asked Bilal: 'What did he do?' Bilal said: 'The Prophet (ﷺ) went to relieve himself, then he performed Wudu', so he washed his hands and face, and wiped his head and he wiped over his Khuffs, then prayed