اَللَّهُمَّ أَنْتَ الْمَلِكُ لَا إِلَهَ إِلَّا أَنْتَ، أَنْتَ رَبِّي وَأَنَا عَبْدُكَ، ظَلَمْتُ نَفْسِي وَاعْتَرَفْتُ بِذَنْبِي فَاغْفِرْ لِي ذُنُوبِي جَمِيعًا إِنَّهُ لَا يَغْفِرُ الذُّنُوبَ إِلَّا أَنْتَ، وَاهْدِنِي لِأَحْسَنِ الْأَخْلَاقِ لَا يَهْدِي لِأَحْسَنِهَا إِلَّا أَنْتَ، وَاصْرِفْ عَنِّي سَيِّئَهَا، لَا يَصْرِفُ عَنِّي سَيِّئَهَا إِلاَّ أَنْتَ.

Allaahumma antal-maliku laa ilaaha illaa anta. anta rabbee wa-anaa ‘abduka, dhalamtu nafsee wa’taraftu bidhanbee faghfir lee dhunoobee jamee'aan innahu laa yaghfirudh-dhunooba illaa anta. wahdinee li-ahsanil-akhlaaqi laa yahdee li-ahsanihaa illaa anta, wasrif 'annee sayyi-ahaa laa yasrifu 'annee sayyi-ahaa illaa anta

O Allah, You are the Sovereign, none has the right to be worshipped except You. You are my Lord and I am Your servant, I have wronged my own soul and have acknowledged my sin, so forgive me all my sins for no one forgives sins except You. Guide me to the best of characters for none can guide to it other than You, and deliver me from the worst of characters for none can deliver me from it other than You.

Reference: Muslim: 771