Sayyidah Aishah Siddiqah (may Allah be pleased with her) reports this saying of the Prophet (peace and blessings be upon him): "Whoever believes in Allah Almighty and the Last Day should not harm his neighbour; whoever believes in Allah Almighty and the Last Day should speak good or else remain silent; and whoever believes in Allah Almighty and the Last Day should honour his guest."
Al-Bazzar recorded it from his teacher Ibrahim bin Yahya al-Naysaburi, whom I do not know, and the rest of its narrators have been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الزهد / 18164