Musnad Ahmad 30:1834

Sa'id ibn Mansur narrated to us, he said: 'Abd al-'Aziz ibn Muhammad narrated to us, he said: Muhammad ibn 'Abd Allah ibn al-Hasan narrated to me, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "When one of you prostrates, let him not kneel as the camel kneels. Let him place his hands, then his knees."