Was Avrohom really born in 1948?

Question

I have always been told that Avrohom Ovinu was born 1948 years after Odom was created. I recently thought I would add up the relevant figures in Sidra Bereisis and Sidra Noach to see what number I would end up with. I followed the logic that Odom begot Sheis at 130 (Gen. 5:3) and Sheis begot Enosh when he was 105 (5:6) making it 235, etc. For example, the posuk (5:32) says that Noach begot Sheim (Chom and Yefes) when he was 500 so I added 500 on to 1056 and got 1556.

Somehow, I ended up with Avrohom being born at 1946 and not 1948. I redid this calculation several times and then on an excel spreadsheet and realized that there aren't any differences between the numbers I put in and the numbers the Toroh says.

I looked up this query on google and found that on this Wikipedia page it says that Avrohom was born in 1948 but that it should be 1946.

Why is there this discrepancy of figures and when was Avrohom actually born - 1948 or 1946?

Answer 1

For example, the posuk (5:32) says that Noach begot Sheim (Chom and Yefes) when he was 500 so I added 500 on to 1056 and got 1556.

But it doesn't say what order they were born in. Rashi later on (10:21) points out that Yefet is older since we know (11:10) Shem was 100 years old only 2 years after the flood, whereas we know (7:6) the flood started when Noach was 600. So Noach must have been 502 when Shem was born, which would make sense if Yefet was born first when Noach was 500. Probably those who calculate to 1948 are using this interpretation of when Shem was born.

Answer 2

You are probably miscalculating the actual age of Noach at the time that Shem was born. Calculate using only the ages given in Noach starting from when Shem fathered Arpachshad. Then add the time to the date of the flood. The timeline in the Art Scroll Chumash (as one example) puts the date of the flood as 1656 AM. I did the timeline myself based on the pesukim and did indeed show Noach was born in 1056 and the flood was in 1656 (as posted in Rabbi Leibtag shiurim: The Hebrew Calendar and its Missing Years- Parts 1 - 3

Noach 11:10

These are the generations of Shem: Shem was one hundred years old, and he begot Arpachshad, two years after the Flood.

If you start from here and add the ages at the birth of each generation, you get (using the 70 years of Terach)

Noach 11:26

And Terah lived seventy years, and he begot Abram, Nahor, and Haran.

a total of 292 years after the flood. This now give 1656 + 292 = 1948.

This assumes that Avraham was the eldest and was born when Terach was 70, unlike Shem who was the definitely born after Yafes (two years after Noach started having children at 500), as shown in the pasuk.

Noach 10:21

And to Shem were also born [children; he was] the father of all the people of the other side [of the river], the brother of Japheth the elder.

Rashi

the brother of Japheth, the elder: I do not know [from the wording of the verse] whether Japheth is the elder or Shem. [The verse may be rendered: the elder brother of Japheth.] When Scripture says (11:10): “Shem was a hundred years old, etc.” two years after the Flood, you must say that Japheth was the elder, because Noah was five hundred years old when he first had children, and the Flood came to pass in the six hundredth year. Consequently, the eldest of his sons was a hundred years old [at the time of the Flood], and Shem did not reach [the age of] a hundred until two years after the Flood. — [from Gen. Rabbah 37:7]

Rashi says Cham was not the youngest, though Rav Hirsch translates Noach 9:24 as his youngest son. However, this does not change the timeline based on 11:10.

And Noah awoke from his wine, and he knew what his small son had done to him.

Rav Hirsch translates this pasuk as:

When Noach awoke from his wine and knew what his youngest son had done unto him.

Rashi

his small son: The worthless and despicable one, like (Jer. 49:15): “Behold I have made you small among the nations; despised among men.” - [from Gen. Rabbah 16:7]