Narrated to me Muhammad ibn al-Muthanna and Ibn Bashshar, both saying: narrated to us Muhammad ibn Ja'far, narrated to us Shu'bah, who said: I heard Qatadah narrating from Anas ibn Malik, from the Prophet, peace and blessings be upon him, who said: "Perform the bowing and prostration properly. By Allah, indeed I see you from behind me — and sometimes he said: from behind my back — when you bow and prostrate."