Musnad Abu Ya'la al-Mawsili 242:1

Ishaq ibn Abi Isra'il narrated to us, Mu'tamir ibn Sulayman narrated to us, he said: I heard Dawud al-Tafawi narrating from Abu Muslim al-Bajali, from Zayd ibn Arqam, who said: The Prophet of Allah, may Allah bless him and grant him peace, used to supplicate at the end of the prayer: "O Allah, our Lord and the Lord of everything, I bear witness that all servants are brothers. O Allah, our Lord and the Lord of everything, make me sincere to You and my family at every moment of the worldly life and the Hereafter, O Possessor of Majesty and Honor. Hear and answer. Allah is the Greatest of the great, the Light of the heavens and the earth. Allah is the Greatest of the great, sufficient for me is Allah, and He is the best Disposer of affairs. Allah is the Greatest of the great."