Musnad Ahmad 788:252

Abu Ahmad narrated to us, he said: Sharik narrated to us, from Abu Ishaq, from Abu Burdah, from Abu Musa, who said: The Prophet, may Allah bless him and grant him peace, used to supplicate with these supplications: "O Allah, forgive me my sins, my ignorance, my extravagance in my affair, and what You know better than I do. O Allah, forgive me my seriousness and my jesting, my mistakes and my intentional acts, and all of that is with me."