Abu Dawud
Purification (Kitab Al-Taharah)
Book Number: 001 / Hadith Number: 23
Narated By Hudhaifah : The Apostle of Allah (pbuh) came to a midden of some people and urinated while standing. He then asked for water and wiped his shoes.
Abu Dawud said: Musaddad, a narator, reported: I went far away from him. He then called me and I reached just near his heals.