Who was the first real Jew by birth, Abraham or Isaac?
Isaac was the first real Jew by birth. Abraham is regarded as the father of the Jewish race because of his call and covenant promises, but his bloodline remained Syrian. Isaac, the son of promise, is therefore identified as the first actual Jew by physical birth.
Les explains that the Jewish nation was not yet on the scene. Abraham had two brothers in Syria, so he was a Syrian; his blood did not change. By his call and covenant promises, Abraham becomes the father of the Hebrew nation, and Scripture considers him the father of the Jewish race and first Jew. Yet genetically, Isaac, the first son of promise, would be the first real Jew by birth. Abraham came out of Ur of the Chaldees and then came down into the land of promise.