Sahih Muslim 660
صحيح مسلم#660SahihAnas b. Malik narrated that a desert Arab (Bedouin) stood in a corner of the mosque and urinated there. The people (the Companions of the Prophet who were present there) shouted, but the Messenger of Allah (ﷺ) said:Leave him alone. When he had finished, the Messenger of Allah (ﷺ) ordered that a bucket (of water) should be brought and poured over it
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 2:126