4:86
وَإِذَاحُيِّيتُمبِتَحِيَّةٍفَحَيُّوا۟بِأَحْسَنَمِنْهَآأَوْرُدُّوهَآ ۗإِنَّٱللَّهَكَانَعَلَىٰكُلِّشَىْءٍحَسِيبًا٨٦
wa-idhā ḥuyyītum bitaḥiyyatin faḥayyū bi-aḥsana min'hā aw ruddūhā inna l-laha kāna ʿalā kulli shayin ḥasīban
And when you are greeted with a greeting, greet [in return] with one better than it or [at least] return it [in a like manner]. Indeed Allāh is ever, over all things, an Accountant.(86)