Al-An'am - 6:54

وَإِذَا جَاءكَ الَّذِينَ يُؤْمِنُونَ بِآيَاتِنَا فَقُلْ سَلاَمٌ عَلَيْكُمْ كَتَبَ رَبُّكُمْ عَلَى نَفْسِهِ الرَّحْمَةَ أَنَّهُ مَن عَمِلَ مِنكُمْ سُوءًا بِجَهَالَةٍ ثُمَّ تَابَ مِن بَعْدِهِ وَأَصْلَحَ فَأَنَّهُ غَفُورٌ رَّحِيمٌ
[6:54]
And when those who believe in Our communications come to you, say: Peace be on you, your Lord has ordained mercy on Himself, (so) that if any one of you does evil in ignorance, then turns after that and acts aright, then He is Forgiving, Merciful.
When those come to thee who believe in Our signs, Say: "Peace be on you: Your Lord hath 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.
And when those who believe in Our revelations come unto thee, say: Peace be unto you! Your Lord hath prescribed for Himself mercy, that whoso of you doeth evil through ignorance and repenteth afterward thereof and doeth right, (for him) lo! He is Forgiving, Merciful.