“Take Aaron and his sons with him, and the garments, and the anointing oil, and the bull of the sin offering, and the two rams, and the basket of unleavened bread;
Then Moses said to Aaron, “Draw near to the altar, and offer your sin offering and your burnt offering, and make atonement for yourself and for the people; and bring the offering of the people, and make atonement for them; as the Lord has commanded.”
By faith Abel offered to God a more acceptable sacrifice than Cain, through which he received approval as righteous, God bearing witness by accepting his gifts; he died, but through his faith he is still speaking.
Therefore he had to be made like his brethren in every respect, so that he might become a merciful and faithful high priest in the service of God, to make expiation for the sins of the people.
He has no need, like those high priests, to offer sacrifices daily, first for his own sins and then for those of the people; he did this once for all when he offered up himself.
(which is symbolic for the present age). According to this arrangement, gifts and sacrifices are offered which cannot perfect the conscience of the worshiper,