Musnad Ahmad 833:3

Yahya ibn Sa'id narrated to us, from Shu'bah, Qatadah narrated to us, from Nasr ibn 'Asim, from Malik ibn al-Huwayrith—and he was one of the companions of the Prophet, peace and blessings of Allah be upon him—who said: "The Prophet, peace and blessings of Allah be upon him, used to raise his hands when he entered into the prayer, when he bowed, and when he raised his head from bowing, up to his ears."