Musannaf Ibn Abi Shayba 1:1855

Hushaym narrated to us, he said: Al-A’mash informed us, from Abu Wa’il, from Hudhayfah, who said: I saw the Messenger of Allah (may Allah bless him and grant him peace) come to a trash heap of some people, and he urinated upon it. Then I brought him water, so he performed ablution and wiped over his leather socks.