Sahih Muslim Book 1, Hadith Number 75.

Chapter : Concerning exhortation to accord honour and respect to the neighbour and the guest and obligation to observe silence except in goodness, and all these qualities come within the orbit of Iman.

It is reported on the authority of Abu Huraira that the Messenger of Allah (may peace be upon him) observed: He who believes in Allah and the Last Day should either utter good words or better keep silence; and he who believes in Allah and the Last Day should treat his neighbour with kindness and he who believes in Allah and the Last Day should show hospitality to his guest.