The parasha interweaves a series of rebellions challenging the authority of Moshe as leader, the status of Aaron and his sons as Kohanim, and the special standing of the tribe of Levi. Korach, a Levite, is jealous and resentful of the positions held by Moshe and Aharon and accuses them of aggrandizing themselves above the community. The Reubenites and the unnamed two hundred and fifty tribal leaders fall in step easily with the assertions made by Datan and Aviram, that Moshe and Aharon have not brought them to a land flowing with milk and honey but to a wilderness.

Moshe responds, first, to the Levites by reminding them of their special status granted by God. He responds to the challenge of Aharon's role as Kohen Gadol by having Korach and his followers bring an offering to see God's response. Korach gathers the whole community to witness the event. Fulfilling Moshe's prophecy, God causes an earthquake which swallows up Datan, Aviram and their followers as a sign that they have rebelled against God. At the same moment, a fire from God consumes all those offering incense. Moshe orders Elazar to gather up the rebels' fire pans, which had become sacred, and fashion them into a cover for the altar as a perpetual reminder of these events.

God is angered by the continued rebelliousness and strikes the community with a plague. Moshe instructs Aharon to make an atonement offering of incense and to stand in the midst of the community to stem the plague.

God commands each tribe to place its tribal staff before the Ark. The staff representing Aharon and the tribe of Levi flowers overnight, affirming their chosenness. The staff is left next to the Ark as a mnemonic device. Aharon, his sons and the Levites are charged with the responsibility for the Tabernacle and the cultic rituals. The parasha concludes with the various rewards and gifts they will receive for their service.

Summary from www.uscj.org