We reasoned in our prior lesson that the Israelites were in Egypt for 215 years (i.e., from Jacob's migration to the exodus). Also, we calculated that it was 215 years from the giving of the promise to Abraham to that migration. In total, 215 + 215 = 430 years, which is what Paul affirmed in Galatians 3:17. We also harmonized chronological data from Genesis and Exodus with Paul's statement.

This position is superior to the alternatives, in my view. All of the related passages in Scripture can be best harmonized with this explanation, and one does not have to treat the references to 400 years as a rounded number or the reference to four generations as non-literal. Furthermore, this view prevents one from having to assume any gaps in Moses' genealogy in Exodus 6. Finally, the 215 year duration fits well with secular history. Though these dates are debatable, a case can be made for the years in Egypt from Jacob to the exodus spanning 1662 - 1447 B.C. The main objection to the above explanation is that some believe it to be mathematically impossible to increase the population of the Israelites from less than 100 males to over 600,000 men in 215 years. But, though the population numbers are challenging, they are not impossible considering that God blessed them with swarms of children (cf. Exo. 1:7).

Let's do a little math together:

If we start with just 32 young males (i.e., grandsons of Jacob) at the time of the migration (cf. Gen. 46), and propose that each one of them would have 5 sons **on average** in 32.5 years, we would have 160 young males after 32.5 years. If this rate continued, we'd have 800 young males after 65 years. We'd have 4000 young males after 97.5 years, 20,000 young males after 130 years, and 100,000 young males after 162.5 years. **Finally, after 195 years, we'd have 500,000 young males. **At 215 years after the migration, Moses led all the Israelite nation out of Egypt. These 500,000 young males would all be **men** at that point (20 years of age or older) and most of their fathers would have still been alive (100,000 men). There were certainly grandfathers and great-grandfathers who were still alive as well, but we don't need to count many of them to harmonize with Numbers 1:45,46 - "So all who were numbered of the children of Israel, by their fathers' houses, from twenty years old and above, all who were able to go to war in Israel--all who were numbered were 603,550." 500,000 + 100,000 + some grandfathers **easily** gets us over the census number recorded after the exodus. Likely there were fewer young men and more older men in actuality, but the math above presents one possible way to get to 603,550 men.

And now, for the objections:

- "But Stephen, your numbers above are an oversimplification of population growth." I agree wholeheartedly, but most of the numbers above are
**conservative estimates**. For example, if a man had 5 sons before he was 32.5 years old, he'd likely have more sons after this age, but we have not counted any of them for our calculating purposes. The numbers above work if the man stops having kids at 32.5 years of age (which is not realistic for that era). Having more sons each generation would make it easier, of course, to get to 603,550 adult men by the time of the exodus, so we don't have to be too firm with the "5 sons per man for his first 32.5 years of life" standard. For example, if a man had only 3 sons by 30 but ended up with 6 or 7 sons by age 50, the population would still grow large enough. All that being said, if a young man married in his teens, it would not be unrealistic for him to have 5 sons by his early 30s, especially since God was blessing the nation with fertility. - "But Stephen, if a man had 5 sons wouldn't he also have 5 daughters, too, on average? Stephen, do you really believe the Israelite families had 10 kids on average by their early 30s?" Friends, why not? I acknowledge that it sounds like a lot from our modern perspective, but when Moses said "the children of Israel were fruitful and increased abundantly, multiplied and grew exceedingly mighty; and the land was filled with them" (Exo. 1:7), it must refer to something extraordinary! Though there is no mention of it, polygamy may have also played a role. We know it certainly helped Jacob's family expand rapidly (i.e., 11 sons in 7 years)!

It should also be noted that we only assumed 32 young males **initially** for our calculating purposes. It may have been more than that, though it is impossible to know for certain how many of those listed in Genesis 46 were actually born prior to the migration (cf. our archived lesson from 06/30/12 for an explanation of this). I mention it at this point only to observe that if the number of initial males was increased, it would result in an average of less than 5 sons being required per male. Furthermore, the following conditions would also get us to the desired number:

- Start with 30 young males and have an average of 7 sons for the first 39 years of life, or
- Start with 50 young males and have an average of 10 sons for the first 48.75 years of life, etc.

Admittedly, much of the population figuring above is speculative, but as long as we have something feasible we can put to rest the challenge some raise about 215 years being an insufficient amount of time for the Israelite population to grow to over 600,000 men.