Hisnul Muslim 63

After the final tashahhud and before salam

اللَّهُمَّ إِنِّي أَسْأَلُكَ يَا اللَّهُ بِأَنَّكَ الْوَاحِدُ الأَحَدُ، الصَّمَدُ الَّذِي لَمْ يَلِدْ وَلَمْ يُولَدْ وَلَمْ يَكُنْ لَهُ كُفُواً أَحَدُ، أَنْ تَغْفِرْ لِي ذُنُوبِي إِنَّكَ أَنْتَ الْغَفُورُ الرَّحِّيمُ

Allaahumma 'innee 'as'aluka yaaAllaahu bi'annakal-Waahidul-'Ahadus-Samadul-lathee, lam yalid wa lam yoolad, wa lam yakun lahu kufuwan 'Ahad, 'an taghfira lee thunoobee 'innaka 'Antal-Ghafoorur-Raheem.

O Allah, I ask You. O Allah, You are the One, the Only, Self-Sufficient Master, Who was not begotten and begets not and none is equal to Him. Forgive me my sins, surely you are Forgiving, Merciful.