Musannaf Ibn Abi Shayba 3:4652

Waki' narrated to us, he said: Sufyan narrated to us, from Habib ibn Abi Thabit, from 'Abd al-Malik ibn Suwayd al-Kahili, that 'Ali performed Qunut in the dawn [prayer] with these two surahs: "O Allah, we seek Your help and we seek Your forgiveness, and we praise You with goodness, and we do not disbelieve in You, and we cast off and abandon whoever acts wickedly against You. O Allah, You alone we worship, and to You we pray and prostrate, and to You we strive and hasten. We hope for Your mercy and we fear Your punishment; indeed, Your severe punishment is attached to the disbelievers."