Volume 1, Book 4, Number 226:

Narrated 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 Apostle went to the dumps of some people and urinated while standing."