Thanks, I’d be interested in seeing it. I’m not knowledgable about the different text, but according to the NABRE the math adds up. (Gen 11:10-26) says Shem was 100 at the birth of Arpachshad and lived another 500 years after that. Abram is born 290 years after the birth of Arpachshad, making Shem 390. And (Gen 25:7) says Abraham lived to be 175, meaning Shem actually outlived him by 35 years.
Before we go there, here is the chart I posted earlier in this thread:
Note that many of the ages don’t match up with each other.
1.) The Masoretic and the Samaritan generally agree with one another over the ages of many of the antediluvian patriarchs when they begat children and when they died, with the exception of Jared (who according to the Samaritan text, was at the modest age of 62 when he first had offspring and died at the age of 847 - in contrast to the Masoretic and Septuagint’s age 162 and 962), Methuselah (was 67 when he had children and 720 when he died), and Lamech (aged 53 when he begat offspring and 653 at the time of his death). The result of this is that in the Samaritan OT, Methuselah is no longer the one who has the longest lifespan at the time of his death, but Adam (at age 930).
2.) When compared to the Masoretic, the Septuagint has a tendency to push the antediluvian patriarchs’ ages when they bore children by a hundred years. Again, the exception to this is Jared (both the Masoretic and the LXX agree that he begat during age 162 and died 800 years later) and Lamech (the Septuagint has 188/753 in contrast to the 182/777 of the Masoretic).
3.) All three agree in saying that Noah had children when he was 502 years old (although the Samaritan text has him die fifty years earlier than both the Masoretic and the Septuagint at age 900), and that Shem begat when he was 100 and died at age 600. Arphachshad is where the Septuagint and the Samaritan begin again to diverge from the Masoretic text.
4.) The Septuagint inserts an extra patriarch in between Arphachshad and Salah, Cainan, not found in both the Samaritan or the Hebrew. (For the record, Cainan can also be found in Luke 3:36)
…the son of Abraham, the son of Terah, the son of Nahor, the son of Serug, the son of Reu, the son of Peleg, the son of Eber, the son of Shelah,
the son of Cainan, the son of Arphaxad, the son of Shem, the son of Noah, the son of Lamech, the son of Methuselah, the son of Enoch, the son of Jared, the son of Mahalaleel, the son of Cainan, the son of Enos, the son of Seth, the son of Adam, the son of God.
5.) Aside from the aforementioned Cainan, both the Septuagint and the Samaritan texts tend to add a hundred years into the ages in which most of the postdiluvian patriarchs had children: the Septuagint does so from Arphachshad to Nahor, with the Samaritan from Arphachshad to Serug (Nahor gets an extra fifty years).
6.) The Samaritan mostly agrees with the Hebrew concerning the ages in which the postdiluvian patriarchs died, with the exception of Eber (died age 404 in Samaritan and Septuagint, fifty years earlier than the Hebrew) and Terah (died age 145, sixty years earlier than the Masoretic’s and Septuagint’s 205).
If we do the math, in the Septuagint version, Shem would have already apparently been dead 19 years before Heber fathered Peleg.
As for Josephus, he generally follows the Septuagint version of the ages, but with a few differences, in that here Shem fathers Arpachshad twelve years after the flood at age 112,
Serug fathers Nahor at age 132, and Nahor fathers Haran at age 120.