Musannaf Ibn Abi Shayba 1:1058

1058. Abd al-Rahim ibn Sulayman narrated to us, from al-Salt ibn Bahram, who said: I saw Ibrahim urinate, then he inserted his hand into the vessel before washing it. He said: So I shouted at him, and he smiled and said: "There is no man more severe regarding this than I am; I did not insert it except while it was pure."