Sahih Bukhari | Volume 8 | Hadith Number 47

Narrated by Abu Huraira
Allah's Apostle said, "Anybody who believes in Allah and the Last Day should not harm his neighbour, and anybody who believes in Allah and the Last Day should entertain his guest generously and anybody who believes in Allah and the Last Day should talk what is good or keep quiet. (i.e. abstain from all kinds of evil and dirty talk).