Musnad Ahmad 32:711

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from Thabit, from Anas, who said: "I have not prayed a prayer after the Messenger of Allah, peace and blessings of Allah be upon him, lighter than the prayer of the Messenger of Allah, peace and blessings of Allah be upon him, while [still] completing the bowing and prostration."