Musnad Abu Ya'la al-Mawsili 129:35

Abu Bakr ibn Abi Shaybah narrated to us, Abd al-Wahhab al-Thaqafi narrated to us, from Humayd, from Anas: That the Prophet, peace and blessings of Allah be upon him, used to raise his hands in the bowing (ruku') and the prostration (sujud).