Musnad Ahmad 1061:0

Abu Humayd al-Sa’idi reported: I was present with the Messenger of Allah (ﷺ) when he prayed. He stood up, raised his hands until they were level with his shoulders, then said "Allahu Akbar" until every bone returned to its place and settled. Then he recited. Then he bowed, placed his hands on his knees as if he were gripping them, bent his back, and when he raised his head, he stood straight until every bone returned to its place. Then he prostrated, placed his hands on the ground without spreading them out or tucking them in, and pointed the tips of his toes toward the Qibla. When he raised his head, he sat on his left foot and straightened his back until every bone returned to its place. Then he prostrated, then stood up and performed the second rak'ah in the same manner. When he stood up after the two rak'ahs, he said "Allahu Akbar" and raised his hands until they were level with his shoulders, just as he did when he began the prayer. He continued in this manner throughout his prayer until, in the final rak'ah, he moved his left foot forward and sat on his hip, then performed the taslim.