Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: Indeed, Mu'adh was an ummah, devoutly obedient to Allah, upright in faith, and he was not of the polytheists. Thereupon Farwah, a man from the tribe of Ashja', said: He has forgotten; (the verse is:) "Indeed, Ibrahim." Sayyiduna Abdullah (may Allah be pleased with him) said: Who has forgotten? We used to liken Mu'adh to Ibrahim. He was asked about the ummah, and he said: The teacher of goodness. And he was asked about the qanit, and he said: The one obedient to Allah and His Messenger.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9908