اللَّهُمَّ إِنِّي ظَلَمْتُ نَفْسِي ظُلْمًا كَثِيرًا، وَلَا يَغْفِرُ الذُّنُوبَ إِلَّا أَنْتَ، فَاغْفِرْ لِي مَغْفِرَةً مِنْ عِنْدِكَ، وَارْحَمْنِي، إِنَّكَ أَنْتَ الْغَفُورُ الرَّحِيمُ
Allāhumma innī ẓalamtu nafsī ẓulman kathīrā, wa lā yaghfirudh-dhunūba illā ant, faghfir lī maghfiratam-min ʿindik, warḥamnī, innaka antal-Ghafūrur-Raḥīm
O Allah, I have wronged myself greatly, and none forgives sins but You. So forgive me with forgiveness from You, and have mercy on me. You are the Forgiving, the Merciful.
Sahih al-Bukhari 834; Sahih Muslim 2705