Musannaf Ibn Abi Shaybah

Hazrat Ubaid bin Umair narrates that I offered the morning prayer behind Umar bin Khattab, and in the Qunoot of Fajr he recited this supplication: O Allah! We seek help from You and ask forgiveness from You. And we praise You in the best manner. And we do not show ingratitude to You. And we separate ourselves from and abandon the one who disobeys You. O Allah! We worship You alone. And for You alone we pray and prostrate. And to You alone we hasten and present ourselves in service. And we hope for Your mercy. And we fear Your punishment. Surely, Your punishment is to be meted out to the disbelievers.