Leviticus Chapter 8
With all preparations for the Tabernacle completed, Aaron and his sons were formally anointed to serve as priests. Aaron, and those who would succeed him as high priest (see the Fact Finder question below), all symbolized the coming ultimate Anointed One, Jesus Christ; in Greek, "Christ" means anointed one (see The Anointed One and What Is Jesus Christ Doing Right Now?).
"The Lord said to Moses [see also The Trysting Tent], "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; and assemble all the congregation at the door of the tent of meeting." And Moses did as The Lord commanded him; and the congregation was assembled at the door of the tent of meeting.
And Moses said to the congregation, "This is the thing which The Lord has commanded to be done." And Moses brought Aaron and his sons, and washed them with water [see also The Origin of Baptism]. And he put on him the coat, and girded him with the girdle, and clothed him with the robe, and put the ephod upon him, and girded him with the skilfully woven band of the ephod, binding it to him therewith. And he placed the breastpiece on him, and in the breastpiece he put the Urim and the Thummim [see Urim And Thummim]. And he set the turban upon his head, and on the turban, in front, he set the golden plate, the holy crown, as The Lord commanded Moses [see Aaron's Turban].
Then Moses took the anointing oil, and anointed the tabernacle and all that was in it, and consecrated them." (Leviticus 8:1-10 RSV)
Leviticus Chapter 9
And so the operation of The Tabernacle In The Wilderness (see also The Camp) and the Levitical priesthood began.
"On the eighth day Moses called Aaron and his sons and the elders of Israel [see also The Senate]; and he said to Aaron, "Take a bull calf for a sin offering, and a ram for a burnt offering, both without blemish, and offer them before The Lord. And say to the people of Israel, 'Take a male goat for a sin offering, and a calf and a lamb, both a year old without blemish, for a burnt offering, and an ox and a ram for peace offerings, to sacrifice before The Lord, and a cereal offering mixed with oil; for today The Lord will appear to you.'" (Leviticus 9:1-4 RSV)
"Then Aaron lifted up his hands toward the people and blessed them; and he came down from offering the sin offering and the burnt offering and the peace offerings.
And Moses and Aaron went into the tent of meeting; and when they came out they blessed the people, and the glory of The Lord appeared to all the people. And fire came forth from before The Lord and consumed the burnt offering and the fat upon the altar; and when all the people saw it, they shouted, and fell on their faces." (Leviticus 9:22-24 RSV)
Leviticus Chapter 10
The Lord (see YHVH, Adonai, Jehovah, LORD) had provided the Levites with a precise code of conduct - and a warning about what would happen if it were violated. The priests were symbols of Christ, and as such could not take it upon themselves to do something on their own, thereby making themselves "false Christs" (see False Christs Of The Old Testament). Unfortunately for two of Aaron's sons, they disregarded their instructions and warnings.
"Now Nadab and Abihu, the sons of Aaron, each took his censer, and put fire in it, and laid incense on it, and offered unholy fire before The Lord, such as He had not commanded them. And fire came forth from the presence of The Lord and devoured them, and they died before The Lord. Then Moses said to Aaron, "This is what The Lord has said, 'I will show Myself Holy among those who are near Me, and before all the people I will be glorified.'" And Aaron held his peace." (Leviticus 10:1-3 RSV)
"And The Lord spoke to Aaron, saying, "Drink no wine nor strong drink, you nor your sons with you, when you go into the tent of meeting, lest you die; it shall be a statute for ever throughout your generations. You are to distinguish between the holy and the common, and between the unclean and the clean; and you are to teach the people of Israel all the statutes which The Lord has spoken to them by Moses."
And Moses said to Aaron and to Eleazar and Ithamar, his sons who were left, "Take the cereal offering that remains of the offerings by fire to The Lord, and eat it unleavened beside the altar, for it is most holy; you shall eat it in a holy place, because it is your due and your sons' due, from the offerings by fire to The Lord; for so I am commanded." (Leviticus 10:8-13 RSV)
Fact Finder: After the deaths of Nadab and Abihu, how did the high priesthood continue through Bible History?
See The Lines Of Eleazar and Ithamar