1 Chronicles 4:15

And the sons of Caleb the son of Jephunneh
Jephunneh is not the same with Hezron, as the Targum, but another son of Kenaz, hence called the Kenezite, ( Joshua 14:6 ) and brother of Othniel; and Caleb his son is the same that was sent one of the spies of the land of Canaan by Moses, see ( Numbers 13:6 ) ( 14:6 )

his sons were Iru, Elah, and Naam;
of whom we nowhere else read:

and the sons of Elah, even Kenaz;
another Kenaz, or rather it should be read Uknaz; so Jarchi and Kimchi.