Musnad Abu Ya'la al-Mawsili 209:127

Abu Khaythama narrated to us, Waki' narrated to us, from Sufyan, Abu 'Awn Muhammad ibn 'Ubaydullah narrated to us, from 'Abdullah ibn Shaddad, he said: I heard Abu Hurayrah saying: "Perform ablution from what fire has touched." He said: So Marwan sent to Umm Salamah and asked her. She said: "The Messenger of Allah (peace and blessings of Allah be upon him) ate a shoulder [of meat] in my presence, then he went out to the prayer and did not touch water."