Genesis 11:10

But to avoid needless prolixity, we shall mention not the number of years each member of this series lived but only the year of his life in which he gave birth to his heir, that we may thus reckon the number of years from the flood to Abraham and may at the same time leave room to touch briefly and cursorily upon some other matters necessary to our argument. In the second year, then, after the flood, Shem when he was 100 years old begat Arpachshad; Arpachshad when he was 135 years old begat Cainan; Cainan when he was 130 years begat Salah. Salah himself, too, was the same age when he begat Eber. Eber lived 134 years and begat Peleg, in whose days the earth was divided. Peleg himself lived 130 years and begat Reu; and Reu lived 132 years and begat Serug; Serug 130, and begat Nahor; and Nahor 79, and begat Terah; and Terah 70, and begat Abram, whose name God afterwards changed into Abraham. There are thus from the flood to Abraham 1, years, according to the common or Septuagint versions. In the Hebrew copies far fewer years are given, and for this either no reason or a not very credible one is given.

When, therefore, we look for the city of God in these seventy-two nations, we cannot affirm that while they had but one tongue, that is, one language, the human race had departed from the worship of the true God. Nor can we conclude that genuine godliness had survived only in those generations that descend from Shem through Arpachshad and reach to Abraham. But from the time when they proudly built a tower to heaven, a symbol of godless exaltation, the city or society of the wicked becomes apparent. Whether it was only disguised before or nonexistent, whether both cities remained after the flood—the godly in the two sons of Noah who were blessed and in their posterity, and the ungodly in the cursed son and his descendants, from whom sprang that mighty hunter against the Lord—is not easily determined.

It is necessary, therefore, to preserve the series of generations descending from Shem, for the sake of exhibiting the city of God after the flood. As before the flood it was exhibited in the series of generations descending from Seth, now it is descending from Shem. And therefore does divine Scripture, after exhibiting the earthly city as Babylon or "Confusion," revert to the patriarch Shem and recapitulate the generations from him to Abraham, specifying the year in which each father gave birth to the son that belonged to this line and how long he lived. And unquestionably it is this that fulfills the promise I made, that it should appear why it is said of the sons of Eber, "The name of the one was Peleg, for in his days the earth was divided." For what can we understand by the division of the earth, if not the diversity of languages? And, therefore, omitting the other sons of Shem, who are not concerned in this matter, Scripture gives the genealogy of those by whom the line runs on to Abraham, as before the flood those are given who carried on the line to Noah from Seth. Accordingly this series of generations begins thus: "These are the generations of Shem: Shem was a hundred years old and begat Arpachshad two years after the flood. And Shem lived after he begat Arpachshad five hundred years and begat sons and daughters." In like manner it registers the rest, naming the year of his life in which each begat the son who belonged to that line that extends to Abraham. It specifies, too, how many years he lived thereafter, begetting sons and daughters, that we may not childishly suppose that the men named were the only men, but that we may understand how the population increased and how regions and kingdoms so vast could be populated by the descendants of Shem.

These are the generations of Shem. Shem was one hundred years old when he begot Arphaxad, two years after the flood. After the destruction of the Tower of Babel, Scripture hastens, by enumerating the generations of the second age of the world (for the first …

That nothing is left upon record concerning those of this line, but their names and ages; the Holy Ghost seeming to hasten thro' them to the story of Abraham. How little do we know of those that are gone before us in this world, even those that lived in the same places where we live! Or indeed of those who are our contemporaries, but in distant places.