Narrated 'Abdullah bin 'Amr ( r a )
A man asked the Prophet ( pbuh ),
"WHAT DEEDS IN ISLAM ARE GOOD?
The Prophet ( pbuh ) replied,
"To feed (others ), and to greet those
whom you know and those who you do not know. "
Sahih AI - Bukhari Vol No. 1
The Book of belief,
Hadith No. 12