Q. Most people would usually accept that Joseph’s age was 39 when he reunited with Jacob, from the sum of the following numbers: He was 30 when he became ruler, then came the 7 years of prosperity and 2 years of futility (Gen 41:46, 53, 45:6). Jacob was 130 at that time (Gen 47:9), so he should have given birth to Joseph when he was (130-39=) 91, substantiated by the biblical account that Jacob bore Joseph when he was old (Gen 37:3). However, my immediate reaction was Joseph appeared to be too young. If he was 39, then Judah would at most be 42 because Judah was the 4th son in a row from Leah while Joseph was the last son (from Rachel) in the second 7 years of Jacob’s servitude, so at most the two would only be 3 years apart. For Judah to be 42, there would be great chronological difficulty, because his son Perez had already been a father of 2 kids at the time of such reunion (Gen 46:12). Though Perez was Judah’ son, age-wise, he could be considered as Judah’s grandson because he was only conceived by Tamar after Judah’s two elder sons Er and Onan became adults, married Tamar and died, so Perez could be considered as the 2nd generation descendant from Judah, and hence his son considered as the 3rd. How could a man aged 42 have a 3rd generation descendant?
A. My first reaction was that Judah as #4, with 6 sons and one daughter (Dinah) in between, got to be more than 3 years older than Joseph’s #11. However, as you rightly pointed out, all 11 sons were born during Jacob’s second 7 years working for Laban. [The first 7 years were for Leah, as Laban cheated Jacob by switching Leah for Rachel; the second 7 years were for Rachel, who was given to Jacob at the beginning of the term; and 6 more years for Jacob’s flock.] Even though there were 4 mothers, with 11 children before Joseph, there needs to be overlapping pregnancies within those 7 years. I worked out one possible version assuming that:
* each pregnancy was full-term at 9 months without any pre-mature births;
* for the same mother, there was a one-month gap between succeeding births due to the ovulation and menstrual cycle;
* for different mothers, there was still a one-month gap as the birth order was clearly identified in Scripture.
This is presented here: Judah’s Age but of course there are many other possibilities if one or more of the assumptions were changed.
Under this scenario Judah was born in the 39th months of the second 7 year term, and Joseph in the 83rd month. So the two are 44 months apart, and Judah is only 3 years and 8 months older than Joseph. At the time of the reunion with Joseph at age 39, Judah would be 42-43 years old. Now, can a 43 year-old man be a great-grand father, since Perez (with 2 sons) was his daughter-in-law Tamar’s son and technically also Judah’s grandson besides being his illegitimate son?
The answer is yes, it’s possible. Under Jewish law a boy becomes a man at age 13 (bar mitzvah), and a girl becomes a woman at age 12 (bat mitzvah). After they become a son or daughter of commandment they are responsible for their own actions and can marry. So technically a male can marry at age 13 and become a father at age 14, a grandfather at age 28, and a great-grandfather at age 42, if his son and grandson all got married and have a child at the same young age as he did. If Perez’s second son was born a year later, Judah would have been 43 then. This is rare but apparently what happened in Judah’s case. Some of these details don’t come out until you do a careful study of the Bible!