Musnad Ahmad 32:1090

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from Qatadah, from Anas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said to me—and that was at the time of the *suhur* (pre-dawn meal)—: "O Anas, I intend to fast, so feed me something." He said: So I brought him dates and a vessel containing water after Bilal had given the call to prayer. He said: "O Anas, look for someone to eat with me." He said: So I called Zayd ibn Thabit. He said: "O Messenger of Allah, I have drunk a drink of *sawiq* (barley meal) and I intend to fast." The Messenger of Allah (peace and blessings of Allah be upon him) said: "And I intend to fast." So he ate the *suhur* with him, and he prayed two rak'ahs, then he went out, and the prayer was called.