Everyone on Earth spoke the same language back then. Some people in Shinar decided to celebrate being human by building a city with a big tower. God didn’t want people building shit unless it was to honor him, and to keep them from doing such a thing ever again, he “confused their language” and spread them out all over the planet. After that, the tower was called Babel.
Two years after the flood, when Shem was 100, he fathered Arpachshad. He lived another 500 years and then he died.
When Arpachshad was 35, he fathered Shelah. He lived another 403 years and then he died.
When Shelah was 30, he fathered Eber. He lived another 403 years and then he died.
When Eber was 34, he fathered Peleg. He lived another 430 years and then he died.
When Peleg was 30, he fathered Reu. He lived another 209 years and then he died.
When Reu was 32, he fathered Seruf. He lived another 207 years and then he died.
When Seruf was 30, he fathered Nahor. He lived another 200 years and then he died.
When Nahor was 29, he fathered Terah. He lived another 119 years and then he died.
When Terah was 70, he fathered Abram, Nahor and Haran.
Haran fathered Lot and Milcah, and later died in Ur of the Chaldeans.
Nahor married his neice, Milcah, and had two kids, Milcah and Iscah.
Abram married Sarai, but she was barren.
Terah took Abram, Sarai and Lot from Ur to Canaan, and they settled in the land of Haran.
I think they were starting to run out of names.

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