Musannaf Ibn Abi Shayba 3:23

Abu Bakr narrated to us, he said: Ghundar narrated to us, from Shu'bah, from al-Hakam, he said: I heard 'Amr ibn Maymun say: 'Umar prayed the morning prayer with us while he was a traveler at Dhu al-Hulayfah, and he was intending [to go to] Makkah. He said: "Allah is the Greatest. 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."