Musannaf Ibn Abi Shayba 3:17

Abu Bakr narrated to us, he said: Abu Bakr ibn Ayyash narrated to us, from Asim, from Abu Wa'il, who said: When Umar would begin the prayer, he would say: "Glory be to You, O Allah, and with Your praise, and blessed is Your name, and exalted is Your majesty, and there is no god other than You," and he would make us hear it.