It is narrated from Sayyiduna Ibn Amr (may Allah be pleased with him) that once the Noble Prophet (peace and blessings be upon him) said: "Do you know who is a Muslim?" The companions (may Allah be pleased with them) replied, "Allah and His Messenger know best." He said: "A Muslim is the one from whose tongue and hand other Muslims are safe." Then he asked, "Do you know who is a believer?" The companions (may Allah be pleased with them) replied, "Allah and His Messenger know best." He said: "A believer is the one from whom the lives and wealth of other believers are safe. And the real emigrant is the one who abandons sins and refrains from them."