اللَّهُمَّ إِنِّي ظَلَمْتُ نَفْسِي ظُلْمًا كَثِيرًا وَلَا يَغْفِرُ الذُّنُوبَ إِلَّا أَنْتَ فَاغْفِرْ لِي مَغْفِرَةً مِّنْ عِندِكَ وَارْحَمْنِي إِنَّكَ أَنتَ الْغَفُورُ الرَّحِيمُ
Allahumma inni dhalamtu nafsi dhulman kathiran wa la yaghfirudh-dhunuba illa Anta faghfir li maghfiratan min 'indika warhamni innaka Antal-Ghafurur-Rahim
O Allah, I have wronged myself greatly, and none forgives sins except You. So grant me forgiveness from Yourself and have mercy on me. Indeed, You are the Forgiving, the Most Merciful.
Abu Bakr (RA) asked the Prophet ﷺ: "Teach me a du'a to say in my prayer." He taught him this one. Abu Bakr — the best man after the prophets, the first to believe, the one who gave everything for Islam — asked for a forgiveness du'a, not a du'a of status. And the Prophet ﷺ gave him one that opens with "I have wronged myself greatly." The greatest men have the deepest humility.
Related Du'as
رَبَّنَا إِنَّنَا آمَنَّا فَاغْفِرْ لَنَا ذُنُوبَنَا وَقِنَا عَذَابَ النَّارِ
Our Lord, indeed we have believed, so forgive us our sins and protect us from the punishment of the Fire.
Sahihأَسْتَغْفِرُ اللَّهَ وَأَتُوبُ إِلَيْهِ
I seek Allah's forgiveness and I repent to Him. (The Prophet ﷺ used to say this more than 100 times a day.)
Sahihرَبِّ اغْفِرْ وَارْحَمْ وَأَنْتَ خَيْرُ الرَّاحِمِينَ
My Lord, forgive and have mercy, and You are the best of those who show mercy.
Sahihرَبِّ اغْفِرْ لِي وَتُبْ عَلَيَّ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ
My Lord, forgive me and accept my repentance. Indeed, You are the Acceptor of Repentance, the Most Merciful.
Sahih