Hadar - This name should be read Hadad as in 1-Chronicles 1:30. This reading is supported by more than three hundred MSS., versions, and printed editions. See Clarke at Genesis 25:18 (note).
Tema - Supposed to be a place in Arabia Deserta, the same of which Job speaks, Job 6:19.
Jetur - From whom came the Itureans, who occupied a small tract of country beyond Jordan, which was afterwards possessed by the half-tribe of Manasseh.
Naphish - These are evidently the same people mentioned 1-Chronicles 5:19, who, with the Itureans and the people of Nadab, assisted the Hagarenes against the Israelites, but were overcome by the two tribes of Reuben and Gad, and the half-tribe of Manasseh.
Kedemah - Probably the descendants of this person dwelt at Kedemoth, a place mentioned Deuteronomy 2:26. I wish the reader to observe, that concerning those ancient tribes mentioned here or elsewhere in the Pentateuch little is known; nor of their places of settlement have we more certain information. On this subject many learned men have toiled hard with but little fruit of their labor. Those who wish to enter into discussions of this nature must consult Bochart's Geographia Sacra, Calmet, etc.

Hadar and Tema,.... From the first of these the city Adra in Arabia Petraea, and from the other the city Themma in Arabia Deserta, both mentioned by Ptolemy (r), may be thought to have their names; or the city Adari and the Athritae in Arabia Felix (s); and the inhabitants of the land of Tema are mentioned as Arabians, Isaiah 21:13; and Pliny (t) speaks of a people called Thimaneans, whom he says the ancients joined to the Nabathaeans: the troops of Tema mentioned in Job were of this people, Job 6:19; and Eliphaz the Temanite, Job 2:11, is thought by some not to be the descendant of Teman the grandson of Esau, but to be of this man's people and country. The three last sons follow:
Jetur, Naphish, and Kedemah; the two first of these are reckoned among the Hagarites, as the Ishmaelites were sometimes called, 1-Chronicles 5:19; from Jetur came the Itureans, whom Pliny (u) places in Coelesyria; and their country Iturea is reckoned by Strabo (w) along with Arabia; and the Ithyreans with Virgil (x) are famous for their bows, as Ishmael and his posterity were for archery in all ages, and still are; see Gill on Genesis 21:20. As for the posterity of Naphish and Kedomah, we have no account elsewhere, nor any traces of their names, unless those of the latter should be meant by the men of the east, or the men of Kedem, Jeremiah 49:28, which is not improbable, since they are mentioned with the posterity of Kedar the second son of Ishmael; and the Nubaeans by Lebanon may be from Naphish.
(r) Geograph. l. 5. c. 17, 19. (s) Ibid. l. 6. c. 7. (t) Nat. Hist. l. 6. c. 28. (u) Nat. Hist. l. 5. c. 23. (w) Geograph. l. 16. p. 520. (x) Georgic. l. 2. ver. 448.