Numeri 16:1

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]:

Ver. 1. The son of Izhar.] And so first cousin to Moses and Aaron; for Izhar was brother to Amram their father. Exo 6:18

Sons of Reuben.] Who, being next neighbours to Korah in the camp, were the sooner corrupted by him.

“ Uvaque corrupta livorem ducit ab uva. ” - Juven.