Numbers 16:1-2

Now Korah the son of Izhar, the son of Kohath, the son of Levi, and Dathan and Abiram the sons of Eliab, and On the son of Peleth, sons of Reuben, took men, and they rose up before Moses and men of the Israelites, two hundred and fifty chiefs of the assembly, famous in the assembly, well-known men.