1 Chronicles 1:38 - Joseph Benson’s Commentary on the Old and New Testaments

The sons of Seir This Seir was not Esau, nor of his posterity, but the ancient lord of this country, from whom it had its name, (see Genesis 36:20,) whose genealogy is here set down, that it might be understood from whom Eliphaz's concubine and the mother of Amalek sprung; and because of that affinity which was contracted between his and Esau's posterity. Those who were not united and incorporated with them, were destroyed by them, Deuteronomy 2:12.