ইংরেজিঃ হাদিস- ২৭

To greet is a part of Islam

Narrated ‘Abdullah bin ‘Amr: A person asked Allah’s Messenger (sallallahu ‘alaihi wa sallam) . “What (sort of) deeds in or (what qualities of) Islam are good?” He replied, “To feed (the poor) and greet those whom you know and those whom you don’t know.”