Invocations after the final Tash-ahhud and before ending the prayer

اللَّهُمَّ إِنِّي ظَلَمْتُ نَفْسِي ظُلْماً كَثِيراً، وَلاَ يَغْفِرُ الذُّنوبَ إِلاَّ أَنْتَ، فَاغْفِرْ لِي مَغْفِرَةً مِنْ عِنْدِكَ وَارْحَمْنِي، إِنَّكَ أَنْتَ الغَفورُ الرَّحيمُ

Allāhumma innī ẓalamtu nafsī ẓulman ka-thīran, walā yaghfiru adh-dhunwba illā anta, fa ighfir lī maghfiratan min ʿindika wa irḥamnī, innaka anta l-ghafwru ar-raḥīm

O Allah, I have indeed oppressed my soul excessively and none can forgive sin except You, so forgive me a forgiveness from Yourself and have mercy upon me. Surely, You are The Most-Forgiving, The Most-Merciful.