Al 'Imran, 135 Ayah
3:135
وَٱلَّذِينَ إِذَا فَعَلُواْ فَٰحِشَةً أَوۡ ظَلَمُوٓاْ أَنفُسَهُمۡ ذَكَرُواْ ٱللَّهَ فَٱسۡتَغۡفَرُواْ لِذُنُوبِهِمۡ وَمَن يَغۡفِرُ ٱلذُّنُوبَ إِلَّا ٱللَّهُ وَلَمۡ يُصِرُّواْ عَلَىٰ مَا فَعَلُواْ وَهُمۡ يَعۡلَمُونَ ١٣٥
Wa Al-Ladhīna 'Idhā Fa`alū Fāĥishatan 'Aw Žalamū 'Anfusahum Dhakarū Al-Laha Fāstaghfarū Lidhunūbihim Wa Man Yaghfiru Adh-Dhunūba 'Illā Al-Lahu Wa Lam Yuşirrū `Alá Mā Fa`alū Wa Hum Ya`lamūna
And those who, when they commit an immorality or wrong themselves [by transgression], remember Allah and seek forgiveness for their sins - and who can forgive sins except Allah ? - and [who] do not persist in what they have done while they know.