It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Whoever believes in Allah and the Last Day should not harm his neighbor; whoever believes in Allah and the Last Day should honor his guest; and whoever believes in Allah and the Last Day should speak good or remain silent.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 9970