Musnad Ahmad 38:1

Rawh ibn ‘Ubadah narrated to us, Shu‘bah narrated to us, al-Hasan ibn ‘Imran—a man who was in Wasit—narrated to us, he said: I heard ‘Abdullah ibn ‘Abd al-Rahman ibn Abza narrating from his father, "That he prayed with the Messenger of Allah (peace and blessings of Allah be upon him), and he would not complete the takbir—meaning—when he lowered [for prostration] and when he raised [from it]."