Volume 1, Book 12, Number 796: bukhari
Narrated Abu Bakr As-Siddiq:
I asked Allah's Apostle to teach me an invocation so that I may invoke Allah with it in my prayer. He told me to say, "Allahumma inni zalumtu nafsi zulman kathiran, Wala yaghfirudhdhunuba illa anta faghfirli maghfiratan min 'Indika, war-hamni innaka antal-ghafururrahim (O Allah!
I have done great injustice to myself and none except You forgives sins, so please forgive me and be Merciful to me as You are the Forgiver, the Merciful)."
Narrated Abu Bakr As-Siddiq:
I asked Allah's Apostle to teach me an invocation so that I may invoke Allah with it in my prayer. He told me to say, "Allahumma inni zalumtu nafsi zulman kathiran, Wala yaghfirudhdhunuba illa anta faghfirli maghfiratan min 'Indika, war-hamni innaka antal-ghafururrahim (O Allah!
I have done great injustice to myself and none except You forgives sins, so please forgive me and be Merciful to me as You are the Forgiver, the Merciful)."