Musnad Ahmad 307:3

'Affan narrated to us, he said: Hammam narrated to us, he said: It was said to Matar al-Warraq, while I was with him: "From whom did al-Hasan take [the narration] that 'he performs ablution from what the fire has changed'?" He said: "He took it from Anas, and Anas took it from Abu Talhah, and Abu Talhah took it from the Messenger of Allah, may Allah bless him and grant him peace."