Thank you for the question on the descendants of Noah, “How does the Bible prove that the Ashkenaz are actually the “house of Edom”?”
As I thought about this question, one needs to make a distinction between proof and prove.
Proof means the evidence or argument establishing a fact or the truth of a statement. Prove means demonstrating the truth or existence of something by evidence or argument.
Here are my thoughts regarding the questions:
A. The “House of Edom” and the “House of Jacob” comes from the line of Isaac and his forefather being Abraham.
Genesis 25 says this, “This is the account of the family line of Abraham’s son Isaac. Abraham became the father of Isaac, 20 and Isaac was forty years old when he married Rebekah daughter of Bethuel the Aramean from Paddan Aram[c] and sister of Laban the Aramean…When the time came for her to give birth, there were twin boys in her womb. 25 The first to come out was red, and his whole body was like a hairy garment; so they named him Esau.[d] 26 After this, his brother came out, with his hand grasping Esau’s heel; so he was named Jacob.[e] Isaac was sixty years old when Rebekah gave birth to them” (NIV).
Genesis 36 lists the lineage and land of Esau’s descendants. “40 These were the chiefs descended from Esau, by name, according to their clans and regions: Timna, Alvah, Jetheth, 41 Oholibamah, Elah, Pinon, 42 Kenaz, Teman, Mibzar, 43 Magdiel and Iram. These were the chiefs of Edom, according to their settlements in the land they occupied. This is the family line of Esau, the father of the Edomites.” (NIV).
Thus in my reasoning the House of Edom and the House of Jacob stems from the grandfather Abraham.
B. The Lineage and Birthplace of Abram and Sarai.
Genesis 11 states the lineage of Abram from Terah, his father. The text says this, “This is the account of Terah’s family line. Terah became the father of Abram, Nahor and Haran. And Haran became the father of Lot. 28 While his father Terah was still alive, Haran died in Ur of the Chaldeans, in the land of his birth. 29 Abram and Nahor both married. The name of Abram’s wife was Sarai, and the name of Nahor’s wife was Milkah; she was the daughter of Haran, the father of both Milkah and Iskah. 30 Now Sarai was childless because she was not able to conceive.” (NIV).
Acts 7 provides additional insight as to the Terah and Abram. Stephen gives this testimony about the Jewish lineage, “To this he replied: “Brothers and fathers, listen to me! The God of glory appeared to our father Abraham while he was still in Mesopotamia, before he lived in Harran. 3 ‘Leave your country and your people,’ God said, ‘and go to the land I will show you.’[a] 4 “So he left the land of the Chaldeans and settled in Harran. After the death of his father, God sent him to this land where you are now living.” (NIV).
One can conclude that Terah with his three sons lived in the land of the Chaldeans where Terah’s third son died in Ur of the Chaldeans. It may be assumed that Terah lived in the general area or even in the city of Ur.
C. The Lineage of Terah to Shem.
Genesis 11 states the lineage of Terah to Shem. “This is the account of Shem’s family line. Two years after the flood, when Shem was 100 years old, he became the father[d] of Arphaxad. 11 And after he became the father of Arphaxad, Shem lived 500 years and had other sons and daughters. 12 When Arphaxad had lived 35 years, he became the father of Shelah. 13 And after he became the father of Shelah, Arphaxad lived 403 years and had other sons and daughters.[e] 14 When Shelah had lived 30 years, he became the father of Eber. 15 And after he became the father of Eber, Shelah lived 403 years and had other sons and daughters…” (NIV).
The Biblical narrative states the lineage of Shem to Terah in Genesis 11. The statement that Shem is the great, great, etc, to Terah. Terah is the father of Abram leads a lineage line to the House of Edom. Thus the Biblical record lists the lineage from Shem to Jacob and Esau.
D. The Lineage of Noah to Shem, Ham, and Japheth.
In Genesis 10, the lineage of Noah and his three sons are listed. In the line of Shem, the Biblical records states this, “Sons were also born to Shem, whose older brother was[h] Japheth; Shem was the ancestor of all the sons of Eber. 22 The sons of Shem: Elam, Ashur, Arphaxad, Lud and Aram. 23 The sons of Aram: Uz, Hul, Gether and Meshek.[i] 24 Arphaxad was the father of[j] Shelah, and Shelah the father of Eber….” (NIV).
Thus from the Biblical narrative point of view, the lineage of Shem DOESN’T list Ashkenez as one of his sons.
E. The Lineage of Japheth lists Ashkenez.
The Biblical text states the lineage of Japheth. “The sons[a] of Japheth: Gomer, Magog, Madai, Javan, Tubal, Meshek and Tiras. 3 The sons of Gomer: Ashkenaz, Riphath and Togarmah. 4 The sons of Javan: Elishah, Tarshish, the Kittites and the Rodanites.[b]” (NIV).
The lineage of Japheth is as follows: Japheth is the father of Gomer and Gomer is the father of Ashkenaz, Riphath, and Togarmah. Thus one can’t prove that Ashkenaz is the father of the “House of Edom.”
SUMMARY: The Bible demonstrates that the lineage of Ashkenaz is to Japheth, while the “House of Edom” is to Shem.
-Kingston