Musannaf Ibn Abi Shayba 3:79

Ibn Fudayl narrated to us, from Husayn, from Sufyan, who said: I heard Umar begin the prayer and say the takbir. He said: "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." Then he sought refuge [in Allah].