Musannaf Ibn Abi Shayba 3:30

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Sufyan and Ali bin Salih, from Abu Ishaq, from Abu al-Haytham, he said: I heard Ibn Umar saying when he would commence the prayer: "Allah is the Greatest, [much] greatness, and glory be to Allah and His praise, morning and evening. O Allah, make it the most beloved thing to me and the thing I fear most."