It was narrated from ‘Abdullah bin ‘Amr, from Abu Bakr A may Allah be pleased with them both, that he said to the Messenger of Allah صلی اللہ علیہ وآلہ وسلم “Teach me a supplication that I may recite in my prayer.” He said: “Say: (Allah, verily I have wronged myself much and there is none who forgives sins except You. Grant me forgiveness from You and have mercy on me, for You are the Oft-Forgiving, Most Merciful).”(Sahih)