So Moses gave Gilead to the clan of Machir son of Manasseh, and they settled there.
And Jair the son of Manasseh,.... By his mother's side, otherwise he was of the family of Judah; for Hezron, of the family of Judah, married a daughter of Machir, the son of Manasseh, by whom he had a son called Segub, who was the father of Jair, Ch1 2:21, the same went and took the small towns thereof; of that part of Gilead given...
Num 32:39-40 Moses gave the Manassites the land which was conquered by them; in fact, the whole of the kingdom of Bashan, including not only the province of Bashan, but the northern half of Gilead (see at Num 21:33-34). Of this the sons of Machir received Gilead, the modern Jebel Ajlun, between the Jabbok (Zerka) and the Mandhur (Hieromax, Jarmuk), because they had taken it...
Commenting on Numbers 32:39-40