In honor of of 10 Shevat 5780, which marks 70 years since the Lubavitcher Rebbe, Rabbi Menachem Mendel Schneerson, assumed leadership, we present this article on the significance of the number 70.

There’s something special about the number 70. Curiously, we see this number coming up over and over in Scripture and Midrash:

  • Seventy nations and languages: The Torah lists 70 descendants of Noah after the Great Flood, and tells us, “These are the families of the sons of Noah . . . the nations were separated on the earth after the flood.”1 From here the sages learn that humanity comprises 70 nations, each with its own language.2
  • Seventy members of Jacob’s family come to Egypt: The Torah tells us that the number of Jacob’s descendants that came down to Egypt was 70 (including Joseph and his sons who were already in Egypt)3 .
  • Seventy elders: More than 200 years later, Moses is told by G‑d to gather 70 elders of the Jewish people to stand together with him.4 Later, the Sanhedrin (the rabbinical high court) would also have 70 judges, plus the head of the Sanhedrin, representing Moses (i.e., 70 plus 1).
  • Seventy “faces” of the Torah: The Midrash tells us that due to the profoundness and multifacetedness of G‑d’s Torah, there are 70 valid ways or perspectives of understanding the Torah (which is one reason given for the 70 members of the Sanhedrin).5
  • Seventy years of exile: Through the prophet Jeremiah, G‑d promised that after the destruction of the First Temple there would be 70 years of the Babylonian exile, after which G‑d would remember and redeem His people.6
  • Seventy holy days: The Midrash calculates that there are 70 Biblical holy days in a solar calendar year (note that by rabbinic decree, Passover, Shavuot and Sukkot are celebrated for an extra day in the diaspora, and Rosh Hashanah is extended into a second day everywhere):
    52 Shabbats
    7 days of Passover
    1 day of Shavuot
    1 day of Rosh Hashanah
    1 day of Yom Kippur
    8 days of Sukkot7
  • Seventy Divine names: In Scripture, G‑d is referred to by many names. In fact, according to the Midrash, He is known by no less than 70 different names.8
  • Seventy names of the Jewish nation: As G‑d’s chosen nation, Israel is a reflection of its Creator. Just as G‑d is referred to in Scripture with 70 different names, so too are the Jewish people.9
  • Seventy names of Jerusalem: The Midrash continues to say that the holy city of Jerusalem, site of the Holy Temple, is also referred to by 70 names in Scripture.10
  • Seventy full years of a person’s life: The Torah tells us that we are commanded to honor the elderly.11 Well, when does “old age” begin? King David says, “The span of our life is 70 years, or, given the strength, 80 years . . .”12 This tells us that only those with “extra strength” reach and surpass the age of 70, and are therefore deserving of honor.13

The fact that the number 70 is mentioned so many times in Scripture indicates the preeminence of this number. What is the significance of the number 70?

Completeness of Nature

The mystics explain that the natural order is represented by the number 7. G‑d chose to create the world in 7 days, resulting in a week that consists of 7 days,14 corresponding to the 7 attributes (Chesed—Kindness, Gevurah—Severity, Tiferet—Harmony, Netzach—Perseverance, Hod—Humility, Yesod—Foundation, MalchutRoyalty).15

Any number times 10 represents the completeness of that number. (Ten is a “full” number, because after after we reach the number 10, we start counting again with 1. For example, the number 11 is 10 plus 1.) Ten corresponds to the 10 mystical sefirot. And 7 times 10 represents the completion of the natural order—each aspect of nature is complete and made up of all 10 sefirot.

Seventy Connected to Leadership

The Lubavitcher Rebbe explains that the number 70 is especially associated with leadership.

In the Mishnah that is recited as part of the Haggadah on the night of Passover, Rabbi Elazar ben Azariah declares: “I am like a man of 70 years old.”16 The Talmud explains that the reason he declared that he was like a man of 70 is that he wasn’t actually 70; in fact, he was only about 18 years old. However, despite his young age, the sages wanted to appoint him as the nassi, leader of the Jewish people. Rabbi Elazar ben Azariah was reluctant due to his age, so a miracle occured and white hairs appeared in his beard, giving him the respectable appearance of a 70-year-old who was fit for the leadership position.17

The Rebbe explains that his appearing specifically as a 70-year-old was not random. Rather, as explained, the number 70 represents the completion or fullness of a person's life, as the verse states, “The span of our life is 70 years . . .”18 Thus the number 70 represents refining one’s 7 attributes (since each attribute is comprised of 10 sefirot) as well as refining the world in general. Only someone who has reached this level of personal and global refinement is fit to be the nassi. Thus, only after Rabbi Elazar ben Azariah’s appearance became that of a 70-year-old was he satisfied that he was fit to be the nassi and leader of the Jewish people.19

What Comes After Seventy?

While the number 70 represents the completion of the natural order, going beyond 70 represents reaching even higher than the natural order, until we ultimately reach the messianic era. May it be speedily in our days!