Sahih Bukhari

Narrated `Abdullah bin `Amr:Abu Bakr As-Siddiq said to the Prophet, ""Teach me an invocation with which I may invoke (Allah) in my prayer."" The Prophet (ﷺ) said, ""Say: Allahumma inni zalamtu nafsi zulman kathiran wala yaghfirudhdhunuba illa anta, Faghfirli maghfiratan min indika war-hamni, innaka antalGhafur-Rahim