Sahih al-Bukhari 217
صحيح البخاري#217SahihNarrated Anas bin Malik:Whenever the Prophet (ﷺ) went to answer the call of nature, I used to bring water with which he used to clean his private parts
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: 4:83