The Genealogy Classroom: Exodus 6

The single best place for study of Bible genealogies is Exodus chapter 6. In this chapter the time decorations that provide the raw data for chronologies are seen in their purest, and most easily learned form.

The Text

The chapter is near the beginning of the Exodus plagues. Moses and Aaron are making their appearances to Pharaoh, and the narrator stops and gives the genealogy of Moses and Aaron. The following is the raw text:

16And these are the names of the sons of Levi according to their generations: Gershom, Kohath, and Merari; and the years of the life of Levi were 137 years. 17The sons of Gershom: Libni, and Shimei, according to their families. 18And the sons of Kohath: Amram, Izhar, Hebron, and Uzziel; and the years of the life of Kohath were 133 years. 19The sons of Merari: Mahli and Mushi; these are the families of the Levites according to their generations. 20And Amram took his uncle's daughter Jochebed, and she bore him Aaron and Moses, and the years of the life of Amram were 137 years. Exodus 6:16-20

Further time references are in the next chapter.

7And Moses was 80 years old and Aaron 83 when they spoke to pharaoh. Exodus 7:7

Curious Features

This genealogy begins before Jacob’s family migrated to Egypt, and ends with the appearances of Moses before Pharaoh. The overall length of this period is established by a bunch of references. Because it is so important to see the problem presented by the text, each reference is presented here:

  • Total Time in Egypt. Three references establish the overall time in Egypt as 430 years.

    40Now the temporary residence of the sons of Israel who lived in Egypt was 430 years. Exodus 12:40

    41And it came to pass at the end of the 430 years, in this very day, that all the hosts of Yahvah went out from the land of Egypt. Exodus 12:41

    17And this I say, that the contract which was previously confirmed of god in an anointing cannot be repudiated and the promise nullified by the law which came 430 years later. Galatians 3:17

  • Total Time as slaves in Egypt After being in Egypt for 30 years, the Israelites became slaves. They were slaves for 400 years following a prophecy spoken to Abraham.

    13And Yahvah said to Abram, Know for sure that your seed will be strangers in a land that is not theirs, and will be in servitude, and will be afflicted for 400 years; Genesis 15:13

The Problem

The problem that must be dealt with here is the odd nature of the Exodus 6 genealogy. Why is there no age at fatherhood? Is the fatherhood age implied? Or is it not needed?

The Raw Data

From Levi through to Moses there are only so many generations where the life length is given at all. The following table simply summaries those generations and their overall life lengths.

Moses himself is not listed in the following list since he was Aaron’s brother, born 3 years after Aaron when Pharaoh was killing babies in the Nile. Aaron was older when they appeared to Pharaoh, 3 years older, and so this is the maximum total number of years given in the genealogy between the first year of Levi’s life and the time when Aaron and Moses appeared before Pharaoh.

Name Life Length
Levi 137 yearsExodus 6:16
Kohath 133 yearsExodus 6:18
Amram 137 yearsExodus 6:20
Aaron 83 yearsExodus 7:7
Total: 490 years

There was a total of 430 years in Egypt, in one verse this was accurate to the day. There was some time, though, between the birth of Levi, to his father Jacob serving his father-in-law in what is now Lebanon and the time when the entire family went down to Egypt.

How many years was that?

The number isn’t given anywhere directly, but the number of people in the family is known. There were 70, or so, that went down to Egypt. This was a considerably larger number than the 17 people who had left Laban’s service when Jacob was having his sons. How many years does it take to grow a family of 17 into a family of 70? Especially when some of them were young boys?

For the sake of argument, this time had to be measured in decades, how many exactly, remains to be seen.

The problem, stated again

So the data is starting to form a more exact question. Levi had to be born some number of decades before the entire family went down to Egypt, where they remained for 430 years, the last 400 years of that time as slaves.

How do we understand the life lengths of the various generations across this same time?

The 490 years listed in the genealogy is six decades longer than the 430 years given for the time in Egypt. This is a possible answer to the number of decades from Levi’s birth until his family went down to Egypt.

BUT: If this is the right answer, then we must think about how those life lengths are functioning. To get 490 years, those life lengths were added up, in effect those lengths were run together end-to-end.

Other Answers

Other passages, primarily the Genesis 5 and 11 genealogies, suggest that fathers become fathers sometime in their 30s, on average, for people being mentioned in the Genesis genealogies.

If we wanted to inject some sort of average fatherhood value into the genealogy of Exodus 6, then there is nowhere enough generations to cover the time in Egypt. An injected fatherhood value does not work.

The other possibility is that there are generations not listed.

It is important to see what is going on. The 430 years in Egypt, plus some number of years, measured in decades, back to Levi’s first year, receives a total of 490 years listed in the genealogy.

For this to work, at a mathematical level, the numerical values must be run together end-to-end, which means that generations are being skipped.

As shown in a previous article, genealogies function through the omission of generations. Genealogies never imply that all of the various tiers in the genealogy are being supplied. In the previous article this appeared to be occasional, following specific purposes for the writer outside of reporting the various tiers in the genealogy.

In this case each of the named generations has a life length measured in years that are running together end-to-end.

Taken together these 2 facts suggest that each tier in the Exodus 6 genealogy has been reported without reporting any of the immediate generations on either side.

Between Levi and Kohath was some number of generations. Those generations are not reported. Levi’s life length is given as running out to Kohath’s generation, then there is a change to Kohath. His life length runs to Amram, but also skipping some number of unnamed generations. This happened at every generational tier, and we know that in part because no generation between Levi and Aaron has an age given when they became the father of the next generation. There is no begoting or fatherhood age.

This literary structure, where time references are decoration on a short-hand form of the genealogy begs a bunch of other questions.


Were the generations tight?

Perhaps there are years unrecorded; years between each generation. How do we know, for example, that this short list of generations didn’t also have skipped generations that also had years attached.

This question is hard to answer at this level of the study.

The simple answer is that we assume the author was purposeful and though he was using a complex genealogical convention he was not trying to be incomplete.

A more complete answer comes when we get the entire chronology figured out. At that point there will be confirming witnesses that the end-to-end reckoning strategy used here was not only right, but confirmed by many other, especially New Testament, accounts of the same time line.

The question of tightness, ie: that there are no gaps of unknown time, can also be addressed by looking at the time of Jacob and its relationship to the Exodus. This too must be answered later, and the answer will be that Levi is born in the 20 years after the start of a 10 fold Jubilee itself the first 20 years in a 500 years period ending at the Exodus. This is the significance of Jacob’s dream of a ladder to heaven that he has on the way to Laban’s house. The 490 years given here in Exodus 6 is in no way hard to contain, there were no gaps, it suggests a birth year for Levi. Bottom line: there are no other years somehow not accounted for in the genealogy.

So, was there other years, ie: years that passed not accounted for in this genealogy? No.

Note: The first person to recognize that this is how genealogies worked, published for the first time in the 1850s, never bothered to ask the question of tight generations, and he mistakenly assumed that generations were not tight. His mistake allowed (mistakenly) for Adam’s birth year to become immensely and unmeasurably distant in time.

The nature of tight generations will return in the articles on the more complex genealogies given in Genesis 5 and 11.

What does this say about designed lives?

If the text means what it says (it does) and this thread of people who are mentioned in Aaron and Moses’ genealogies lived lives of the given, and end-to-end life lengths, then what does it say about God’s design for this family?

First, it suggests that these men, at least, had life lengths that were designed. The Psalmist hints at this in Psalm 90, every one of us has a designed life.

12So teach us to number our days that we may apply our hearts to wisdom. Psalms 90:12

Further the end-to-end nature of these lives suggest that there was a macro design going on across the family. As that family grew from Levi alone down across the centuries to Moses there was a design feature that after certain members died, another was born in the next year.

Remember, Moses had thousands of brothers and sisters, great-great-great grandchildren of Levi. Each member of this single thread in the growing family of descendants from Levi passed away and the next year was the first year of a new generation.

This pattern is actually seen at times in families even today. Someone dies and the next year, or so, a new member joins the family. Even popular songs have picked up on this common pattern in human lives and families.

Is it reincarnation? No, I don’t think so.

A more biblical explanation would be if the guardian angel for Levi was relieved of his duty at the time when Levi died. That same angel, the one who was watching out for the leader of the clan, now needed another generation to tend and care for. That generation is born in the following year, ready to be the object of the angel’s continued attention. That conservation of angelic time is apparently what is going on across the generations from Levi all the way to Moses and Aaron. The genealogy is telling us the path of that angelic (or perhaps Divine) attention, having started with Levi and ending with Aaron and Moses.

Of course the pattern may well have continued well past Aaron’s generation, it may follow the family even to this day. Support for this idea rests in the Levitical covenant being unconditionally everlasting, which means it must be resident in a descendant of Levi even now.

Playing with Numbers

To help reinforce the idea that the genealogy of Levi to Aaron and Moses, recorded as it is in Exodus 6, is a shortening of the reality of what happened with the family on the ground we stop and look at the numbers.

The population figures at the Exodus are known, over 600,000 male heads of households, old enough to fight in war, were numbered in the Exodus from Egypt. Though total figures are not known they can be estimated. Each male, has a wife, or 1,200,000, roughly speaking. Those families are really adults in their 20th year or more. The children are still not included, but probably represent 1/3 of the overall population. The total population is thus somewhere in the 1,800,000 range or better. 2,000,000 or more is not out of bounds for a total population as brought out of Egypt.

The starting numbers are roughly known. Jacob is the patriarch of the family and he returns with roughly 17 in his family when he leaves Laban. For our purposes here a round number of 20 will be used. By the time his family goes down to Egypt it is now, round numbers again, 70 members strong.

Some members are going to be old and not having kids, but there will also be some percentage that are actively having kids.

The following table shows a generational doubling pattern, where each on-the-ground generation goes up by a factor of 2 at each successive tier. The total number from that and 2 previous generations is shown as the total number for each tier.

For this to have actually worked with this way, where each generation doubles the number of people alive each family needed to have 4 children on average, 2 boys and 2 girls, who made it to adulthood and themselves had 2 boys and 2 girls in their own families.

The table shows the rough numbers at each generation and how big the community would be at that generation.

Tier Number Total Notes
1 1   Jacob
2 20   Left Laban
3 50 71 To Egypt family size.
4 100 170  
5 200 350  
6 400 700  
7 800 1,400  
8 1,600 2,800  
9 3,200 5,600  
10 6,400 11,200  
11 12,800 22,400  
12 25,600 44,800  
13 51,200 89,600  
14 102,400 179,200  
15 204,800 358,400  
16 409600 716,800  
17 819,200 1,433,600 Approaching Exodus census counts
18 1,638,400 2,867,200 Past Exodus census counts

The following table shows that with these rough starting numbers, and with a quadrupling in each generation. This means that each family, on average in Egypt needed to have 8 children, 4 boys and 4 girls that made it to adulthood and themselves had 8 children. Note that this is aggressive.

Tier Number Total Notes
1 1   Jacob
2 20   Left Laban
3 50 71 To Egypt family size.
4 200 270  
5 800 1,050  
6 3,200 4,200  
7 12,800 16,800  
8 51,200 67,200  
9 204,800 268,800  
10 819,200 1,075,200 Approaching Exodus census counts.

The bottom of this table is about 1 tier short of actual numbers that came out of Egypt. In other words, at 8 children per family per tier it would take about 10 generations to go from Jacob at 1 until the Exodus with somewhere like 2,000,000 members.

Note that there is evidence that the average time between generations is something like 30 or so years. Most of the known ages at fatherhood are in the range of 30 to 35 years.

10 generations would take 350 years as a minimum, and these numbers at each generation are probably too aggressive.

The actual experience of the Israelites in Egypt was somewhere between 10 and 17 generations at somewhere around 20 to 30 years in each generation.

OK, so compare this with the 5 generations given in the genealogy from Levi to Aaron/Moses. The average age at fatherhood must approach 100 years and the number of children in each household goes to roughly 16. 8 boys, 8 girls, who reach adulthood and also have 8 boys and 8 girls. Both of these numbers are untenable.

The point, of course, is that the genealogical record of Exodus 6 is a compression from some higher number of generations actually lived.

Why These Names?

Let me say, as a matter of conclusion, that these generations, the ones listed in the genealogy, are actually a family roll call or honor roll of the fathers that were worthy of honor.

Not all fathers are worth of honor and the admonition to honor your father Ephesians 6:2 has important limits. Father’s don’t deserve honor unconditionally. An alcoholic or abusive father demands derision.

With an advanced Bible Book Order related study we can show that these compressed genealogies are the only members in the genealogy who were deserved of honor. Given that there were likely more than twice this number of generations on the ground, then only about 1/2 of the tiers in the genealogy were deserved of honor. Many would suggest the same ratio applies today. These lists of names found in genealogies are fundamentally honor rolls when they are crossing wide swaths of generations.


This article has shown various issues surrounding the end-to-end life lengths found in genealogies. It used Exodus 6 since it is uncluttered with age-at-fatherhood. It established that there is a conservation of time going by in these genealogies suggesting an angel was transfered from the individuals listed in these generations.

The article then explored issues related to generational expansion. Given the overall time in Egypt, and the general age at first fatherhood, there needed to be over 10 generations that had children "on the ground" while in Egypt. Each generation would have had over 4 children on average in each household.

Finally, this article offered an unsupported reason why these names are listed. They are honor rolls. Only the men who deserved honor were listed by name.

With this material well understood, it is time to turn to the question of Adam’s genealogy and the time from Adam to the flood.

Phil Stone, Updated 2016-11-04