New Defender's Study Bible Notes
1:38 sons of Seir. See Genesis 36:20-28. Esau’s daughter-in-law, Timna (I Chronicles 1:35-36) was a daughter of Seir. Thus the descendants of Esau and Seir were related by marriage and, in effect, the Edomites included both tribes. Timna was the mother of Amalek, but it is likely that he had been named after some previous Amalek, who was the real father of the Amalekites.