John Gill Bible Commentary

And these are the names of the dukes that came of Esau,.... After the regal monarchy ceased, the government in Edom was by dukes, and of these there were two sons, one of which an account has been given of already, who were partly of the race of Seir, and partly of the race of Esau; and who were dukes not by succession, but together, in and over their respective families: and it may be observed, that neither Esau, nor his sons by his two first wives, Eliphaz and Reuel, are called dukes, only his three sons by his last wife; all the rest are his grandsons and sons of the two former, which seems to give some light as to the time when those dukedoms took place; and very probably it was by the joint influence of Seir and Esau, whose families had intermarried, that an end was put to the regal power, and who, for a course of years, governed in the above manner: and they of Esau's race in those times are said to be "dukes in the land of Edom", as a learned man (o) has observed; whereas those that follow, which are a second race of them, are called "dukes of Edom", Gen 36:43; who took possession of the country and ruled in it, driving out the Horites and succeeding in their stead: these are described according to their families; they were the heads of: after their places, by their names; the places where they lived, which were called after their names, and are as follow: Duke Timnah, Duke Alvah, Duke Jetheth; these were both the names of the dukes, and of the places where they governed, called after their names; so Timnah or Themna, as Jerom calls it, is by him said to be a city of the princes of Edom, the same he says of Jetheth (p), so the like may be concluded of Alvah. (o) Shuckford's Connection, p. 192. (p) De loc. Heb. fol. 92. F. 95. C.