Numbers 3:1-4 Aaron’s sons (the priests) were Nadab, Abihu, Eleazar, and Ithamar. Nadab and Abihu offered strange fire to God and were disqualified. Eleazar and Ithamar took their place as priests with their father Aaron.
Notes: Of all the tribe of Levi, only the sons of Aaron were priests. All of the future priests came from Eleazar and Ithamar with Eleazar later receiving the greater blessing (See Numbers Chapter 25 for the reason why).
Numbers 3:5-10 The rest of the tribe of Levi were to minister to the 3 priests and the tabernacle. Any one that came near to the tabernacle were put to death.
Numbers 3:11-17 The eligible (one month old and up) Levites (Levi’s sons being Gershon, Kohath, and Merari) were taken instead of every firstborn of Israel that the Lord first instituted prior to the Exodus when the Lord struck the firstborn of the Egyptians.
Notes: The firstborn was to act as the family priest. But when the full ministry of the Mosaic economy came in, God transferred the priestly duties to the Levites, perhaps partly because of their holy zeal in the golden calf incident. In the last plague, every firstborn male Egyptian and every firstborn of their cattle died, but the Israelite boys and cattle were spared. So after this, all Israelite firstborn boys and cattle were dedicated to God. That meant the cattle were sacrificed and the boys should have served God in the sanctuary. But after the golden calf incident, the Levites took the place of the firstborn boys.
Numbers 3:18-26 The Gershonites totaled 7,500 and were to camp behind the tabernacle on the west and guard the furnishings and entrance of the tabernacle.
Numbers 3:27-32 The Kohathites totaled 8,600 and was to guard the sanctuary. They were to camp on the south. They guarded the ark, table, lampstand, altars, vessels, and the screen.
Numbers 3:33-37 The Merarites totaled 6,200. They were to camp on the north. They guarded the frames of the tabernacle, bars, pillars, bases, and accessories. The also guarded the pillars around the court, with their bases and pegs and cords.
Numbers 3:38-51 On the East side of the tabernacle was Moses, Aaron, and his sons guarding the sanctuary itself to protect the people of Israel so they would not be put to death if they came near the tabernacle. The total number of Levites for service was 22,000. They then counted only the firstborn male of all the people of Israel and it numbered, 22,273. The Levites were a substitute for the all the firstborn males of all the people of Israel, but there were 273 more than the count of the Levites. To redeem the remaining number, they were to take 5 shekels from the Israelites for each of the 273 as a redemption price. They were to give that money to Aaron which totaled 1,365 shekels.
Notes: Eleazar oversaw the Kohathites, and Ithamar oversaw the Gershonites and Merarites. 1,365 silver shekels weighed about 170 lbs. The location of the priests at the east side of the tabernacle guarding its entrance may anticipate the role of Jesus as high priest, giving his people access to God’s presence in heaven.