Musnad Ahmad 27:227

Yahya narrated to us, Malik narrated to us, al-Zuhri narrated to me, from Salim, from his father, who said: When the Messenger of Allah (peace and blessings of Allah be upon him) began the prayer, he would raise his hands level with his shoulders. When he bowed, he would do the same. When he raised his head from bowing, he would do the same. And when he said, "Allah hears those who praise Him," he would say, "Our Lord, and to You is the praise." And he would not do that in prostration.