وَإِذَا حُيِّيتُم بِتَحِيَّةٍ فَحَيُّوا۟ بِأَحْسَنَ مِنْهَآ أَوْ رُدُّوهَآ ۗ إِنَّ ٱللَّهَ كَانَ عَلَىٰ كُلِّ شَىْءٍ حَسِيبًا
When you are greeted with a salute, greet with a better one than it, or return it; indeed Allah takes account of all things.