It is narrated from Sayyiduna Abu Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The people should be led in prayer by their best reciter of the Book of Allah and the one who emigrated first. If they are equal, then the one most knowledgeable of the Sunnah. If they are equal in that too, then the one oldest in age. No one should be led in prayer within the area of his authority, nor should anyone sit in his place of honour except with his permission."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14680