Sahih al-Bukhari 226
صحيح البخاري#226SahihNarrated Abu Wail:Abu Musa Al-Ash`ari used to lay great stress on the question of urination and he used to say, "If anyone from Bani Israel happened to soil his clothes with urine, he used to cut that portion away." Hearing that, Hudhaifa said to Abu Wail, "I wish he (Abu Musa) didn't (lay great stress on that matter)." Hudhaifa added, "Allah's Messenger (ﷺ) went to the dumps of some people and urinated while standing
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: 4:92