And Timna was concubine to Eliphaz Esau's son; and she bare to Eliphaz Amalek: these were the sons of Adah Esau's wife. Timna was concubine to Eliphaz - As Timna was sister to Lotan the Horite, Genesis 36:22, we see how the family of Esau and the Horites got intermixed. This might give the sons of Esau a pretext to seize the land, and expel the ancient inhabitants, as we find they did, Deuteronomy 2:12.
Amalek - The father of the Amalekites, afterwards bitter enemies to the Jews, and whom God commanded to be entirely exterminated, Deuteronomy 25:17, Deuteronomy 25:19.