﴿ وَإِذَا حُيِّيتُم بِتَحِيَّةٍۢ فَحَيُّوا۟ بِأَحْسَنَ مِنْهَآ أَوْ رُدُّوهَآ ۗ إِنَّ ٱللَّهَ كَانَ عَلَىٰ كُلِّ شَىْءٍ حَسِيبًا ﴾

“But when you are greeted with a greeting [of peace], answer with an even better greeting, or [at least] with the like thereof. Verily, God keeps count indeed of all things.”

Please check ayah 4:87 for complete tafsir.