Sahih Bukhari
Good Manners and Form (Al-Adab)
Volume: 008 / Book Number: 073 / Hadith Number: 160
Narrated Abu Huraira:
The Prophet said, "Whoever believes in Allah and the Last Day, should serve his guest generously; and whoever believes in Allah and the Last Day, should unite the bond of kinship (i.e. keep good relation with his Kith and kin); and whoever believes in Allah and the Last Day, should talk what is good or keep quit. "