وَاِذَا حُيِّيْتُمْ بِتَحِيَّةٍ فَحَيُّوْا بِاَحْسَنَ مِنْهَا͏ٓ اَوْ رُدُّوْهَاؕ اِنَّ اللّٰهَ كَانَ عَلٰي كُلِّ شَيْءٍ حَسِيْبًا ٨٦
Translation
When you are greeted with a salute, greet with a better one than it, or return it; indeed Allah takes account of all things.