Surah Al-An'am (The Cattle), Verse 54

وَاِذَا جَآءَكَ الَّذِیْنَ یُؤْمِنُوْنَ بِاٰیٰتِنَا فَقُلْ سَلٰمٌ عَلَیْكُمْ كَتَبَ رَبُّكُمْ عَلٰی نَفْسِهِ الرَّحْمَةَ اَنَّهٗ مَنْ عَمِلَ مِنْكُمْ سُوْٓءًا بِجَهَالَةٍ ثُمَّ تَابَ مِنْ بَعْدِهٖ وَاَصْلَحَ فَاَنَّهٗ غَفُوْرٌ رَّحِیْمٌ ۟

Wa izaa jaaa'akal lazeena yu'minoona bi Aayaatinaa faqul salaamun 'alaikum kataba Rabbukum 'alaa nafsihir rahmata annahoo man 'amila minkum sooo'am bijahaalatin summa taaba mim ba'dihee wa aslaha fa annahoo Ghafoorur Raheem

“When those come to thee who believe in Our signs, Say: "Peace be on you: Your Lord has inscribed for Himself (the rule of) mercy: verily, if any of you did evil in ignorance, and thereafter repented, and amend (his conduct), lo! He is Oft-forgiving, Most Merciful.”

Quran 6:54 (Yusuf Ali Translation)