Numbers 26:9

These are the heads of their fathers’ households. The sons of Reuben, Israel’s firstborn: Hanoch and Pallu, Hezron and Carmi; these are the families of Reuben.

“These are they who were called upon by the congregation, the leaders of their fathers’ tribes; they were the heads of divisions of Israel.”

Now Korah the son of Izhar, the son of Kohath, the son of Levi, with Dathan and Abiram, the sons of Eliab, and On the son of Peleth, sons of Reuben, took others,

and they rose up before Moses, together with some of the sons of Israel, 250 leaders of the congregation, those called upon by the assembly, men of renown.

the sons of Reuben the firstborn of Israel were Hanoch and Pallu, Hezron and Carmi.