It is important to observe that the Chronicler gives a lot of space to the offspring of Esau/Edom; in fact, almost half of the chapter is taken up with it. The writer provides diverse and unrelated lists of names associated with the offspring of Esau: the sons of Esau
(1 Chronicles 1:35–37), the sons of Seir
(1 Chronicles 1:38–42), the kings who reigned in the land of Edom
(1 Chronicles 1:43–51) and the chiefs of Edom
(1 Chronicles 1:51–54). The link between Esau, Edom and Seir is made quite plain in Genesis 36:9. The question is, Why is this extensive coverage given to Esau and his descendants?
The likely answer is that Israel (later Judah) and Esau/Edom were brother nations (Deuteronomy 2:4, Deuteronomy 2:8; Malachi 1:2) They were the twin siblings of Rebekah and Isaac (Genesis 25:23–26). The two brothers were destined to live most of their lives in hostility toward one another, a conflict that had its origin already in pregnant Rebekah’s womb. The children struggled together within her…. So she went to inquire of the Lord. And the Lord said to her, 'Two nations are in your womb, and two peoples from within you shall be divided; the one shall be stronger than the other, the older shall serve the younger'
(Genesis 25:22–23).
The two brothers had a troubled relationship from the start, and although they were later reconciled to one another at Penuel, it was lacking in true brotherly affection, though indeed infused with mutual respect. It was then that Esau moved eastward to the rugged terrain of Seir to establish what would later become Edom. The relationship between their descendants, however, was violent and bloody. “Given the history of enmity between Ju-dah and Edom, particularly resulting from Edom’s actions at the time of the Babylonian sacking of Jerusalem (e.g., Psalm 137:7; Ezekiel 35:1–15), the level of detail and lack of animosity in Chronicles are striking."1 The genealogy points to a common heritage of the two brothers, not only as sons of Adam but also, more closely, as descendants of Abraham and Isaac.
43 These are the kings who reigned in the land of Edom before any king reigned over the people of Israel: Bela the son of Beor, the name of his city being Dinhabah.