Question:

Is it true that the Torah tells us that the longest a person can live is 120 years? I have always been told that, and would like to have it confirmed.

Response:

In Genesis 6 we read about the wickedness of Noah’s generation. In verse 3 the Torah says, “The L‑rd said, ‘Let My spirit not quarrel forever concerning man, because he is also flesh, and his days shall be a hundred and twenty years.’”

I must point out that the ancient targumim (Aramaic interpretive translations), and most of the classical Jewish commentators, explain “his days shall be a hundred and twenty years” to mean that G‑d had decided to give the generation of the Flood 120 years to improve. If they would improve their ways, they would be saved; if they would not repent before 120 years elapsed, their days would be over, and G‑d would cleanse the world with a flood.

Ibn Ezra tells us that there are those who understand this verse to cap the lifespan of humans from that time and on to 120 years. He rejects this position, as there were many—including the Patriarchs—who lived longer than 120 years, and it was not until the days of Moses that we see people passing away before reaching that age.

In spite of the above, there is room in Jewish tradition to link this verse to the fact that virtually no one lives past 120, and only special people like Moses merit reaching this milestone.

So what are we to do with Ibn Ezra’s observation? Rabbi Menachem Mendel of Lubavitch (known as the Tzemach Tzedek) explains that the gradual decline of lifespans—which reached 120 only with Moses—was the result of Noah’s sacrifices, which served to temper the severity of the divine decree.