Korach

Numbers 16:1 - 18:32

Korach incites a mutiny challenging Moses' leadership and the granting of the kehunah ("priesthood") to Aaron, accompanied by Moses' erstwhile foes, Dathan and Aviram. Joining them are 250 distinguished members of the community, who offer the sacrosanct ketoret (incense) to prove their worthiness for the priesthood. The earth opens up and swallows the mutineers, and a fire consumes the ketoret-offerers. 

G-d commands that a terumah ("uplifting") from each crop of grain, wine and oil, all firstborn sheep and cattle, and other specified gifts be given to the Kohanim. 

A subsequent plague is stopped by Aaron's offering of ketoret. Aaron's staff miraculously blossoms and brings forth almonds to prove that his designation as High Priest is Divinely ordained.