Korach קרח
a Levite who led a revolt against Moshe and Aharon
Korach is the son of Yitzhar, grandson of Kehat, cousin of Moshe and Aharon. He was a prominent man: a Levite of high family, a bearer of the sacred vessels, and by midrash immensely rich — «rich as Korach» became a proverb.
His slogan sounded impeccable: «The whole community is holy, and the Lord is among them; why do you raise yourselves above the assembly?» Midrash records his sophistries: does a house full of Torah scrolls need a mezuzah? Does a garment entirely of blue wool need a blue thread? The logic was hard to argue with; the aim was power.
Datan and Aviram of Reuven joined him, with 250 chiefs of the community. Moshe proposed a test of incense. Next morning the earth «opened its mouth» and swallowed the ringleaders with their households, and fire consumed the 250.
The Torah adds: «but the sons of Korach did not die». Their descendants sang in the Temple, and eleven psalms bear their name. The Mishnah makes Korach's dispute the model of an argument not for the sake of Heaven.