a reminder to the Israelites that no outsider, who is not of the descendants of Aaron, shall approach to offer incense before the Lord, so as not to become like Korah and his congregation, just as the Lord had said to him through Moses.
By faith Abel offered to God a more acceptable sacrifice than Cain’s. Through this he received approval as righteous, God himself giving approval to his gifts; he died, but through his faith he still speaks.
Unlike the other high priests, he has no need to offer sacrifices day after day, first for his own sins and then for those of the people; this he did once for all when he offered himself.