Genesis 10:1 KJV [1] Now these are the generations of the sons of Noah, Shem, Ham, and Japheth: and unto them were sons born after the flood. https://bible.com/bible/1/gen.10.1.KJV
Shem was the line through whom the messiah was reckoned…Though not emphatically stated I wonder who the eldest was.
Genesis 10:1 KJV [1] Now these are the generations of the sons of Noah, Shem, Ham, and Japheth: and unto them were sons born after the flood.https://bible.com/bible/1/gen.10.1.KJV
Genesis 10:5 KJV [5] By these were the isles of the Gentiles divided in their lands; every one after his tongue, after their families, in their nations. https://bible.com/bible/1/gen.10.5.KJV
The isles of the Gentiles, as at this point in history there was no Israel for there to be Gentiles. They being called gentiles at this stage indicates the position of the author and the narrative as at when this was being written
Genesis 10:5 KJV [5] By these were the isles of the Gentiles divided in their lands; every one after his tongue, after their families, in their nations.https://bible.com/bible/1/gen.10.5.KJV
Genesis 10:21 KJV [21] Unto Shem also, the father of all the children of Eber, the brother of Japheth the elder, even to him were children born. https://bible.com/bible/1/gen.10.21.KJV
The children of eber (meaning from the other side are the Hebrews). They came from the other side of the Euphrates according to dakes commentary.
Genesis 10:32 KJV [32] These are the families of the sons of Noah, after their generations, in their nations: and by these were the nations divided in the earth after the flood. https://bible.com/bible/1/gen.10.32.KJV
So from the beginning we were all one people