Hadad here and in 1 Chronicles 1:50 is the well-known Syrian name, of which Hadar (margin) is an accidental corruption, consequent on the close resemblance between "d" (daleth) and "r" (resh) in Hebrew, the final letters of the two names.

Mishma, and Dumah, Massa, Hadad, and Tema,

Hadad: also called, Hadar

30. Dumah-Dumah and Tema, the great Arab tribes of Beni Teman. Thus this writer [Historical Geography of Arabia] traces the names of all the heads of the twelve tribes of Ishmael as perpetuated in the clans or tribes of the Arabs in the present day.

28-54 The genealogy is from hence confined to the posterity of Abraham. Let us take occasion from reading these lists of names, to think of the multitudes that have gone through this world, have done their parts in it, and then quitted it. As one generation, even of sinful men, passes away, another comes. Ec 1:4; Nu 32:14, and will do so while the earth remains. Short is our passage through time into eternity. May we be distinguished as the Lord's people.