Apostolic Constitutions

Neither do we permit the laity to perform any of the offices belonging to the priesthood; as, for instance, neither the sacrifice, nor baptism, nor the laying on of hands, nor the blessing, whether the smaller or the greater: for "no one taketh this honour to himself, but he that is called of God." For such sacred offices are conferred by the laying on of the hands of the bishop. But a person to whom such an office is not committed, but he seizes upon it for himself, he shall undergo the punishment of Uzziah.