Jair the son of Manasseh. This hero of Manasseh is mentioned here for the first time; in Deuteronomy 3:14 his conquests are somewhat more fully described. His genealogy, which is instructive and suggestive, is given here.
See chart, Genealogy of Jair
It will be seen that Segub, the father of Jair, was a Machirite in the female line only. His father Hezron, according to 1 Chronicles 2:21, married the daughter of Manasseh in his old age, when his elder sons were probably already fathers of families. It may probably be conjectured also that Manasseh, who must have inherited exceptional wealth (cf. Genesis 48:17), and had but one grandson, left a large portion to his grand-daughter, the young wife of Hezron. It was therefore very natural that Segub should have attached himself to the fortunes of his mother's tribe. Is it not also very probable that Machir had other daughters (cf. Genesis 1:23), who also inherited large portions from their grandfather, and whose husbands were willing enough to enter into a family which had apparently brighter prospects than any others? If so, it would account at once for the existence of a large family of Machirites not descended from Gilead, and not on the most friendly terms with the rest of the tribe. It is quite possible that many of the more adventurous spirits amongst the tribe of Judah joined themselves to a family whose reputation and exploits they might naturally claim as their own (see on Joshua 19:34). The small towns thereof, or, "their villages." Septuagint, τὰς ἐπαύλεις αὐτῶν, i.e. the hamlets of the Amorites who dwelt in Argob (Deuteronomy 3:14), the modern district of el Lejja, on the north-western waters of the Yermuk or Hieromax. And called them Havoth-jair. חָוּתֹ יָאִיר. Septuagint, τὰς ἐπαύλεις ἰαίρ, and so the Targums. The word chavvoth only occurs in this connection, and is supposed by some to be the plural of חַוָּה, "life." There does not, however, seem to be anything except the very doubtful analogy of certain German names in favour of the rendering "Jair's lives." It is more likely the corruption of some more ancient name. There is some discrepancy in subsequent references to the Chavvoth-jair. According to 1 Chronicles 2:22, Jair had twenty-three towns in Gilead; from 10:4 it appears that the sons of the later Jair had thirty cities "in the land of Gilead" which went under the name of Chavvoth-jair; while in Joshua 13:30 "all the Chavvoth-jair which are in Bashan" are reckoned at sixty. The plausible, though not wholly satisfactory, explanation is, that the conquests of Nobah came to be subsequently included in those of his more famous contemporary, and the vague name of Chavvoth-jair extended to all the towns in that part of Gilead, and of Bashan too (see notes on the passages cited).