Musannaf Ibn Abi Shayba 3:61

Hushaym narrated to us, he said: 'Abd al-Hamid ibn Ja'far al-Ansari informed us, from Muhammad ibn 'Amr ibn 'Ata' al-Qurashi, who said: I saw Abu Humayd al-Sa'idi with ten men from the companions of the Prophet, may Allah bless him and grant him peace. He said: "Shall I not tell you about the prayer of the Prophet, may Allah bless him and grant him peace?" They said: "Go ahead." He said: "I saw him, when he said the takbir at the opening of the prayer, he raised his hands. And when he bowed, he raised his hands. And when he raised his head from bowing, he raised his hands. Then he would remain standing until every bone settled into its place. Then he would descend prostrating and say the takbir."