Jamieson, Fausset and Brown on 1 Chronicles 2:23

23. he took--rather "he had taken." This statement is accounting for his acquisition of so large a territory; he got it by right of conquest from the former possessors.

Kenath--This place, along with its group of surrounding villages, was gained by Nobah, one of Jair's officers sent by him to capture it (Nu 32:1, 2).

All these belonged to the sons of Machir--In their number Jair is included as having completely identified himself by his marriage and residence in Gilead with the tribe of Manasseh.