Sayyiduna Fadalah bin Ubayd (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said during the Farewell Hajj: "Shall I not tell you about the believer? The believer is the one whom people trust with their wealth and their lives; the Muslim is the one from whose tongue and hand the Muslims are safe; the mujahid is the one who strives against his own self in obedience to Allah; and the emigrant (muhajir) is the one who abandons errors and sins."
Hadith Referenceالمعجم الكبير للطبراني / باب الفاء / 15887