Exodus 29:9

Therefore thou and thy sons with thee shall keep your priest’s office for every thing of the altar, and within the vail; and ye shall serve: I have given your priest’s office unto you as a service of gift: and the stranger that cometh nigh shall be put to death.

And he brought the other ram, the ram of consecration: and Aaron and his sons laid their hands upon the head of the ram. And he slew it; and Moses took of the blood of it, and put it upon the tip of Aaron’s right ear, and upon the thumb of his right hand, and upon the great toe of his right foot. And he brought Aaron’s sons, and Moses put of the blood upon the tip of their right ear, and upon the thumbs of their right hands, and upon the great toes of their right feet: and Moses sprinkled the blood upon the altar round about. And he took the fat, and the rump, and all the fat that was upon the inwards, and the caul above the liver, and the two kidneys, and their fat, and the right shoulder: And out of the basket of unleavened bread, that was before the Lord, he took one unleavened cake, and a cake of oiled bread, and one wafer, and put them on the fat, and upon the right shoulder: And he put all upon Aaron’s hands, and upon his sons’ hands, and waved them for a wave offering before the Lord. And Moses took them from off their hands, and burnt them on the altar upon the burnt offering: they were consecrations for a sweet savour: it is an offering made by fire unto the Lord.

For the Lord thy God hath chosen him out of all thy tribes, to stand to minister in the name of the Lord, him and his sons for ever.

And thou shalt anoint them, as thou didst anoint their father, that they may minister unto me in the priest’s office: for their anointing shall surely be an everlasting priesthood throughout their generations.

And ye shall not go out of the door of the tabernacle of the congregation in seven days, until the days of your consecration be at an end: for seven days shall he consecrate you.

And he hath brought thee near to him, and all thy brethren the sons of Levi with thee: and seek ye the priesthood also?

And there came out a fire from the Lord, and consumed the two hundred and fifty men that offered incense.

To be a memorial unto the children of Israel, that no stranger, which is not of the seed of Aaron, come near to offer incense before the Lord; that he be not as Korah, and as his company: as the Lord said to him by the hand of Moses.

And he shall have it, and his seed after him, even the covenant of an everlasting priesthood; because he was zealous for his God, and made an atonement for the children of Israel.

And thou shalt appoint Aaron and his sons, and they shall wait on their priest’s office: and the stranger that cometh nigh shall be put to death.

And take thou unto thee Aaron thy brother, and his sons with him, from among the children of Israel, that he may minister unto me in the priest’s office, even Aaron, Nadab and Abihu, Eleazar and Ithamar, Aaron’s sons.

And for Aaron’s sons thou shalt make coats, and thou shalt make for them girdles, and bonnets shalt thou make for them, for glory and for beauty. And thou shalt put them upon Aaron thy brother, and his sons with him; and shalt anoint them, and consecrate them, and sanctify them, that they may minister unto me in the priest’s office.

For Moses had said, Consecrate yourselves to day to the Lord, even every man upon his son, and upon his brother; that he may bestow upon you a blessing this day.

Called of God an high priest after the order of Melchisedec.

And no man taketh this honour unto himself, but he that is called of God, as was Aaron. So also Christ glorified not himself to be made an high priest; but he that said unto him, Thou art my Son, to day have I begotten thee.

If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need was there that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron? For the priesthood being changed, there is made of necessity a change also of the law. For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar. For it is evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood.

And they truly were many priests, because they were not suffered to continue by reason of death: But this man, because he continueth ever, hath an unchangeable priesthood. Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them. For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens; Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people’s: for this he did once, when he offered up himself. For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, maketh the Son, who is consecrated for evermore.