Musnad Ahmad 129:7

Muhammad ibn Ja'far narrated to us, Sa'id narrated to us, from Qatadah, from Nasr ibn 'Asim, from Malik ibn al-Huwayrith, that he saw the Messenger of Allah (peace and blessings of Allah be upon him) raise his hands when he intended to bow, and when he raised his head from bowing, and when he raised his head from prostration, until he aligned them with the lobes of his ears.