In the tent of meeting, outside the curtain that is before the covenant, Aaron and his sons shall tend it from evening to morning before the Lord. It shall be a perpetual ordinance to be observed throughout their generations by the Israelites.
So bring with you also your brothers of the tribe of Levi, your ancestral tribe, in order that they may be joined to you and serve you while you and your sons with you are in front of the tent of the covenant.
And you shall say to them: This is the offering by fire that you shall offer to the Lord: two male lambs a year old without blemish, daily, as a regular offering.
Now if perfection had been attainable through the Levitical priesthood—for the people received the law under this priesthood—what further need would there have been to speak of another priest arising according to the order of Melchizedek rather than one according to the order of Aaron?