Musannaf Ibn Abi Shayba 3:171

Abu Bakr narrated to us, he said: Abu al-Ahwas narrated to us, from Abu Ishaq, from al-Harith, who said: When Ali would raise his head from bowing, he would say: "Allah hears those who praise Him. O Allah, our Lord, to You is the praise. By Your might and Your power, I stand and I sit."