Musnad Abu Ya'la al-Mawsili 147:3

Nasr ibn Ali narrated to us, Ziyad ibn al-Rabi’ narrated to us, Abu ‘Imran al-Jawni narrated to us, from Anas ibn Malik, who said: "I do not recognize anything that was [practiced] during the time of the Messenger of Allah, may Allah bless him and grant him peace." It was said to him: "Then where is the prayer, O Abu Hamzah?" He said: "Have you not done regarding the prayer what you have already known?"