Who knows three hundred forty three?

שלושה וארבעים ושלוש מאות - מי יודע?‏

The traditional Passover song "Echad - mi yodeya" implies a possible presupposition that there is a Jewish significance to be found for each natural number. Accordingly, there is an ongoing series on Mi Yodeya that is attempting to unearth significant Judaism facts about each number, in sequence.

What significant Judaism facts are there about the number 343? The more significant within Judaism and the more intrinsically dependent on the value 343, the stronger the answer. Please include sources for your information wherever possible, as with all other answers on this site.

Please don't bring down a rain of lazy gematria answers. I want answers that are genuinely about the number and that also offer up some knowledge about Judaism.

4 Answers 4


Rashi on Shoftim 5:31 says that the strength of the sun when Moshiach comes will be 343 times what it is now.

  • How does he know this?
    – Double AA
    Dec 22, 2016 at 20:07
  • @DoubleAA 7 days of creation cubed. But your question remains very much in force.
    – WAF
    Dec 23, 2016 at 0:19
  • @DoubleAA Apparently from the Midrash Tanchuma. Maybe the source there elaborates more on this.
    – Isaac Moses
    Dec 23, 2016 at 3:51
  • @DoubleAA It looks like the calculation is based on a hit from Yeshayahu 30:26: "shiv'atayim (7^2) ke-or shiv'at hayamim (X7)."
    – Isaac Moses
    Dec 23, 2016 at 3:58

343 is the maximum number of non-d'Oraisa Moed days in a year. That is to say: Calculate the days of the chagim d'Oraisa as celebrated in Chutz La'aretz.

385 (leap year, Malei) - 2 days RH - 1 day YK - 9 days Sukkos and Shmini Atzeres - 8 days Pesach - 2 days Shavuos = 363 days

In a leap year that's malei, Rosh Chodesh Cheshvan, Kislev, Teves, Adar I, Adar II, Iyar, Tammuz, and Elul are all two days, while the others are only one day. We don't need to worry about Tishrei because of RH, leaving twenty days of Rosh Chodesh. Subtracting these from our count of 363 days leaves a grand total of 343 days.

  • 1
    Isn't Yom Tov Sheni only Derbanan?
    – Double AA
    Dec 23, 2016 at 18:38
  • I meant the Chagim that were d'Oraisa as celebrated in Chutz La'aretz. I'll edit to make clearer.
    – DonielF
    Dec 25, 2016 at 0:05
  • 1
    That seems like a more arbitrary rule.
    – Double AA
    Dec 25, 2016 at 3:54

According to Josephus (Wars, book 7, chapter 10), the temple of Onias (Chonyo) stood 343 years until it was shut down. (Critics say this should be edited to 243.) This legitimacy of this temple in Judaism is discussed in the Bavli M'nachos, daf 109. See also Wikipedia.


343 is the least possible number of dates in the year on which a person is permitted to eat chamets. 353 days in a chaser year, minus 8 days of Pesach, and Tisha B'av and Yom Kippur. (The minor fasts only apply during the daytime, not for the entire date.

  • The minor fasts apply for part of the night too actually. But you are right that it needn't be the whole date.
    – Double AA
    Feb 14, 2017 at 16:07

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