Nearly all Tanna’im agree that about 150 years before the destruction of the First Temple, when the king of Assyria exiled the tribes of Reuven, Gad, and half of Menashe, shemita and yovel ceased to apply by Torah law. These mitzvot apply by Torah law only when Israel dwells properly in its Land, with the majority of each tribe in its inheritance (Arakhin 32b; Peninei Halakha: Shemita Ve-yovel 5:4, note 3). Thus, when the Men of the Great Assembly sanctified the Land with respect to shemita and yovel, the conditions for Torah obligation had not yet been restored. During the Second Temple period, therefore, the Jewish people were obligated to observe them by rabbinic enactment. That sanctification remained effective for the future as well: when Israel returns to its Land, each tribe to its inheritance, shemita and yovel will again apply by Torah law, without any need to sanctify the Land again.
Even after the destruction of the Second Temple, the rabbinic obligation to observe shemita was not nullified. True, uncertainty emerged regarding which year is the seventh year. In addition, some Rishonim maintain that once the court that sanctified the months and counted the years no longer functioned – about 300 years after the destruction of the Second Temple – the obligation of shemita ceased as well. According to them, observing shemita today is proper only as a pious practice (Razah and Raavad). In practice, however, the overwhelming majority of Rishonim and Aḥaronim maintain that even today one must observe shemita by rabbinic enactment, following the accepted count transmitted to us (Peninei Halakha: Shemita Ve-yovel 5:6–7, notes 5–6).
One must observe shemita in gevul olei Mitzrayim and Syria as well. However, the prohibition of sefiḥim – produce that grew on its own during shemita – was enacted specifically for gevul olei Bavel, not for gevul olei Mitzrayim or Syria (Rambam, Sefer Mitzvot Gadol, Sefer ha-Ḥinukh, and others). Some authorities are even more lenient and maintain that in gevul olei Mitzrayim and Syria, shemita produce may be eaten even after the time of bi’ur. According to another view, produce grown there does not have the sanctity of shemita at all. [17]
