Musnad Ahmad 30:3361

Muhammad ibn Abdullah narrated to us, Ibn Abi Dhi’b narrated to us, from Sa’id ibn Sam’an, from Abu Hurayrah, who said: The people have abandoned three things that the Messenger of Allah, peace and blessings of Allah be upon him, used to practice. The Messenger of Allah, peace and blessings of Allah be upon him, used to: "When he stood for prayer, he would raise his hands extended, then he would remain silent for a brief moment before the recitation, asking Allah for His bounty, and he would say 'Allahu Akbar' whenever he lowered or raised [his body]."