Sahih al-Bukhari 188
صحيح البخاري#188SahihAbu Musa said:The Prophet asked for a tumbler containing water and washed both his hands and face in it and then threw a mouthful of water in the tumbler and said to both of us (Abu Musa and Bilal), "Drink from the tumbler and pour some of its water on your faces and chests
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 4:54