Sahih Muslim
The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness (Kitab Al-Dhikr)
Book Number: 035 / Hadith Number: 6563
Abu Musa Ash'ari reported on the authority of his father that Allahs Apostle (may peace be upon him) used to supplicate in these words:" O Allah, forgive me my faults, my ignorance, my immoderation in my concerns. And Thou art better aware (of my affairs) than myself. O Allah, grant me forgiveness (of the faults which I committed) seriously or otherwise (and which I committed inadvertently and de- liberately. All these (failings) are in me. O Allah, grant me forgiveness from the fault which I did in haste or deferred, which I committed in privacy or in public and Thou art better aware of (them) than myself. Thou art the First and the Last and over all things Thou art Omnipotent."