Sahih al-Bukhari 224
صحيح البخاري#224SahihNarrated Hudhaifa:Once the Prophet (ﷺ) went to the dumps of some people and passed urine while standing. He then asked for water and so I brought it to him and he performed ablution
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: 4:90