Numbers 16:1-2

Korah, Dathan, Abiram, and On turned against Moses. (Korah was the son of Izhar, the son of Kohath, the son of Levi; Dathan and Abiram were brothers, the sons of Eliab; and On was the son of Peleth; Dathan, Abiram, and On were from the tribe of Reuben.) These men gathered two hundred fifty other Israelite men, well-known leaders chosen by the community, and challenged Moses.