Sahih Muslim Book 1, Hadith Number 78.

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 narrated on the authority of Abu Shuraih al-Khuzai’ that the Prophet (may peace and blessings of Allah be upon him) observed: He who believes in Allah and the Last Day should do good to his neighbour and he who believes in Allah and the Last Day should show hospitality to the guest and he who believes in Allah and the Last Day should either speak good or better remain silent.