Musnad Ahmad 32:1986

Yazid ibn Harun narrated to us, Shu'bah informed us; and Bahz narrated to us, Shu'bah narrated to us; and Hajjaj narrated to us, Shu'bah narrated to us, from Qatadah, from Anas ibn Malik, from the Prophet, peace and blessings of Allah be upon him, who said: "Do not practice continuous fasting (wisal)." They said: "O Messenger of Allah, you practice continuous fasting." He said: "I am not like one of you. I spend the night—and Bahz said: I spend the day or I spend the night—being fed and given to drink."