The sayings of our beloved Prophet Muhammad (Sallallaahu `alayhi wa sallam),
“Among the best deeds are to feed the poor and the deserving and to greet those whom you know and those whom you do now know”
Sahih Al-Bukhari Hadith No. 826 Book 2 Chapter 6. Narrated by Abdullah bin Umar (Radiyallaahu `anhu).