Sunan Abi Da'ud

Narrated Hudhaifah : The Apostle of Allaah ( sal Allaahu alayhi wa sallam ) 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 narrator, reported: I went far away from him. He then called me and I reached just near his heals.