Jamieson, Fausset and Brown on 1 Chronicles 2:55

55. the families of the scribes--either civil or ecclesiastical officers of the Kenite origin, who are here classed with the tribe of Judah, not as being descended from it, but as dwelling within its territory, and in a measure incorporated with its people.

Jabez--a place in Judah (1Ch 4:9).

Kenites that came of Hemath--who settled in Judah, and were thus distinguished from another division of the Kenite clan which dwelt in Manasseh (Jud 4:11).