Sahih Muslim 726
صحيح مسلم#726SahihA'isha reported:The Messenger of Allah (ﷺ) washed himself with water from a vessel (measuring seven to eight seers) because of sexual intercourse
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: 3:48