330. Seven Squared: The obligation to count seven groups of seven years

After the land of Israel was conquered, the Jews were to count Shemittah cycles. Each cycle was seven years, so seven of these cycles was 49 years. The fiftieth year was to be Yoveil, the Jubilee year. This is analogous to the way in which we count seven weeks – 49 days – and the fiftieth day is the holiday of Shavuos. In fact, the Sanhedrin counted years and cycles the same way we count days and weeks. (Refer back to Mitzvah #306.)

The reason for this mitzvah is that in the Jubilee year, land reverts to its original owners. This is in recognition of the fact that God is the true owner of the land. He divvied it up among the Tribes and families of Israel. When we “sell” land in Israel, what we’re really doing is leasing it for a certain number of years until the next Yoveil. This shows that the land really belongs to God and it is not ours to do with as we please. We count the years to acknowledge this reality.

This mitzvah is incumbent upon the Sanhedrin, not upon individuals. It only applies in Israel and even there only when all of the Tribes reside there. (It did not begin until all the Tribes were settled on their land and it ceased when the first Tribes were exiled.)

This mitzvah is discussed in the Talmud in tractates Rosh Hashana (9b, 30a and elsewhere) and Kiddushin (38b). It is codified in the Mishneh Torah in the tenth chapter of Hilchos Shemittah and is #140 of the 248 positive mitzvos in the Rambam’s Sefer HaMitzvos.