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Moshe was 80 when he approached Par'o before the makos, and the makos lasted a year, so he turned 81 in the Adar before the Jews left Mitzrayim. As he turned 120 in the Adar before the Jews entered Israel, the Jews were in the desert only 39 years. What gives?

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Great question! This gives me more places in the Torah where numbers in narrative are clearly not historically accurate, but rather are teaching ideas. –  avi Jul 13 '11 at 7:14
I just heard a drash a few days ago that when the Torah gives a round number it means 1 less. So the 70 souls going into egypt were 69, or when it says 40 lashes it means 39. You could say that here when it says Moshe was 80 he was really 79. I don't like the answer but it's cute. –  avi Jan 10 '12 at 9:17
@Avi, would that imply that Moshe died at 119? –  Seth J Oct 19 '12 at 2:20
I have a slight theory that the age is counted as in a year from 1 Nisan to 29th of the final Adar, with the age of the birthday within that year. So as we had passed 1st Nisan he would have his 80th birthday later that year. My own theory, no source, other than the reign of kings is often counted this way. –  CashCow Jan 13 at 15:06

5 Answers 5

Seder Hadorot tells us that Moshe Rabbeinu was born in the year 2368.

It then tells us that G-d spoke to Moshe at the burning bush on the 15th of Nissan in the year 2447. This would mean that Moshe had just turned 79 a little over a month before, on the 7th of Adar. Moshe then goes to talk to Pharoah when he is 79.

(Incidentally, the Seder HaDorot brings many different opinions of when each of the plagues happened, but see the GR"A on Seder Olam, who says that the 12 months the Mishna says Egypt was plagued starts from G-d appearing to Moshe at the burning bush.)

The Exodus from Egypt was a year later, on the 15th of Nissan in the year 2448, when Moshe had recently turned 80.

Moshe then passes away 40 years later on the 7th of Adar, in the year 2488. Moshe was 120 years old and this was the 40th year the Jews were in the Desert.

The question remains: Why would the Passuk say the Moshe was 80, if he was only 79? I'd have to answer, Miktzas Shana K'shana, part of a year can be considered as a whole year (Rashi in Devarim 13:33 uses this logic to calculate how people could have died in the desert before they were 60). Since Moshe had already started his 80th year, the Torah calls him 80.

One possible problem with this. Seder HaDorot tells us that Aharon was 3 years older than Moshe, and born in 2365, based on the passuk quoted in the question. If Moshe was 79 when he visited Pharoah, would we have to say that Aharon was really 82, in his 83rd year? I guess this would depend on which day Aharon was born, which I did not see written in the Seder HaDorot.

The Kehot Interpolated Chumash says explicitly (bold is chumash text, regular is interpolated commentary):

7 Moses was ten months short of 80 years old and Aaron was 83 years old when they spoke to Pharaoh in the year 2447.

However, the source the are quoting from (Likutei Sichot vol 20, p. 26, note 15) doesn't actually say 10 months, it says "less than 79 and a half". The Lubavitcher Rebbe is using our verse (Shemot 7:7) to prove that someone can be called a certain age, once they have entered that year. In our case, Moshe was called 80 even though he had only entered his 80th year, but was still 79.

It appears that the Kehot Chumash says 10 months because the Lubavitcher Rebbe (in Likutei Sichot vol 6, p. 59, note 18) says that according to the simple understanding of Rashi (Shemot 7:25), as well as the Midrashim that Rashi was based on, there were 3 weeks of warnings before every plague (except Makat Bechorot), even the ones where no warning was mentioned. The Kehot Chumash on verse 7:25 says:

Each plague lasted a month: Moses and Aaron spent three quarters of the month informing Pharaoh about what was going to happen and warning him of the consequences of his obstinacy, and the plague itself lasted a week. Thus, the ten plagues spanned a time-period of ten months.

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Thank you. As you note, there is still a problem with the pasuk that says Moshe was eighty. (Or, more precisely, a problem with Seder Hadoros's saying he wasn't eighty.) But at least this provides more information. –  msh210 Jun 23 '11 at 20:12
Actually, let's consider: I'm not sure how Seder Hadoros can say that Aharon was born in 2365 - he passed away on Rosh Chodesh Av 2487, aged 123, and since הקב"ה ממלא שנותיהם של צדיקים מיום ליום, we can assume he was born on that date too, which would place his birth date in 2364. So it would work out nicely: when they first came to speak to Pharaoh (sometime between Nissan and Av 2447), Aharon was in his 83rd year and Moshe in his 80th. –  Alex Jun 24 '11 at 6:12
@Alex: Does it say anywhere that Aharon was born on Rosh Chodesh Av? We know that not every Tzaddik passes away on the day he was born. Maybe the Torah emphasizes that Moshe passed away on the day he was born to tell us that he did, but Aharon (and maybe Miriam) didn't. –  Menachem Jun 24 '11 at 15:39
@Menachem: I thought I saw it somewhere, but I haven't been able to find it. Fair enough, then - we might assume, as you said, that מקצת השנה ככולה, so Aharon was in his 123rd year when he passed away - i.e., he was born sometime between 1 Av 2364 and 29 Tammuz 2365. Based on the verse in Shemos, then, we might further limit the possible timeframe to Av 2364 through Adar 2365, and thus say that in Nissan 2447 he would indeed have already entered his 83rd year. –  Alex Jul 6 '11 at 18:27
@Alex: and it appears the Seder Hadorot would narrow it down even further, from Tishre 2365. –  Menachem Jul 6 '11 at 18:51

The first plague lasted 7 days. The next 7 plagues lasted 1 day each. The darkness lasted 3 days. From darkness to Passover was 14 days for a total of 31 days...........The 40 year increments of Moses's life are accurate.........

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Welcome to Mi Yodeya, Frank! The question has a given assumption, based on valid sources. If you are merely disagreeing with the assumption and its sources, you aren't really answering the question. –  yEz Dec 1 '14 at 23:12
@YeZ As phrased, it doesn't answer the question; if the answer would quote sources, then it could be a good answer. –  Shokhet Dec 1 '14 at 23:39
@Shokhet I'm not sure how. It would answer how if you took different assumptions then you wouldn't have a question. But it wouldn't be pointing out a flaw in the assumptions given, and therefore wouldn't be answering the question according to those sources. In other words, if he proved the Mishna in eduyos wrong, then sure. But you don't prove a Mishna wrong. –  yEz Dec 2 '14 at 1:05
Ah, I didn't realize that one of the sources cited by the question was a mishna; got it. ( as an aside, you might reinterpret the mishna in Rishonim; or find a midrash that explains the pessukim in a different way....but it's not likely ) –  Shokhet Dec 2 '14 at 2:20
@YeZ Shokhet It's not a year from the first plague but from Moshe's return from Egypt (see the prooftext in TYT). Not entirely clear when the first plague itself was. –  Double AA Dec 2 '14 at 2:38

The Da'as Zkeinim (and the Chizkuni) at the beginning of Parshas Noach addresses this issue in a different context - The posuk says תמים by Noach, and the Midrash says (Bereishis Rabba 30:8) that anyone described as such lived to an age the which is the multiple of 7 (full שבוע). Noach's 950 do not add (or divide) up. He answers that he lived this amount from the time which the Torah described him as תמים, the 350 years after the Mabul. However, there is an extra year, the year of the Mabul itself, which came after he was described as תמים! Says the Da'as Zkeinim:

סלק שנת המבול שאינה נחשבת לפי שנשתנו בה סדרי בראשית

Remove the year of the Mabul, which is not counted because the order of Creation was altered

So a year in which the laws of nature are suspended does not count.

This answers a very similar question to your own:

the Torah says that Noach was 600 at the start of the flood (Bereishis 7:6), and that he lived 350 years after the flood (Bereishis 9:28), and that he lived a total of 950 years (Bereishis 9:29). So what happened to the year of the flood? It isn't counted, as above.

Similarly by the age of Moshe, the year of the Makkos was not counted as a year of his life, as it was a year in which the laws of nature were not firmly in place (I can't find the medrash which says this explicitly, but I have a team of scholars working on it). Thus, Moshe was still 80 for the count of his years when they left Egypt, and there were 40 years in the desert before he died at 120.

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It is possible that when the Chumash says Moshe was 80 that it either is rounding (79 rounded up to 80) or that it does not mean right then, but that at some point in the year long process of speaking to Pharaoh, Moses was 80 (that potion being the final 5 weeks in Egypt, when admittedly, Moses really wasn't speaking to Pharaoh).

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Do you have a source for this? WADR, the rounding doesn't sound right, as Aharon's age is given exactly (i.e., without rounding) in the same pasuk. And the "some point in the process" doesn't sound right either, as it says "when they spoke" — in fact, IIRC, one of the commentaries on that pasuk says explicitly that it means when they first spoke. –  msh210 Jun 23 '11 at 15:58
I can't say I have specific sources for either of these possibilities, which is why I mention them only as possibilities. There are other places where numbers are rounded, especially numbers ending in nine, though none occur to me at the moment. Perhaps in the censuses? –  Ze'ev Felsen Jun 24 '11 at 2:13

Moshe was 79 plus when he came first to pharaoh. His 80th birthday preceded the Exodus. He died about 40 days before Israel enterred the land which was exactly 40 years after the Exodus. When a person is past 79 he is in his 80th year, which is what the Torah refers to.

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Welcome to Judaism.stackexchange.com; I hope you stick around and enjoy. Do you have a source for this answer? –  msh210 Jun 23 '11 at 15:56
If Moshe was 79 and then there was one year of plagues and 40 years in the desert, that would make Moshe 120 years old at death. If so, he would have been in his 121st year, which the Torah, according to your theory, should call 121. –  jake Jun 23 '11 at 18:15
@jake, but it was his birthday. Arguably (perhaps), even if this answer is correct, only after the birthday would be called "121" and not on it. –  msh210 Jun 23 '11 at 19:42

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