Moshe’s final message to Yehoshua included instructions regarding the mitzvah of Hakhel: every seven years, during the year following the Shemittah year, the entire Jewish nation should gather in the Beis Hamikdash, the Holy Temple, to hear the king read select portions of the Torah.
Why was this mitzvah not taught earlier, when Bnei Yisrael were instructed in the observance of Shemittah?
The mitzvah of Hakhel, more so than other mitzvos—including those that are likewise only obligatory in the Land of Israel—is particularly associated with the change that Bnei Yisrael were about to experience at the end of their desert journey.
The Rambam describes the observance of Hakhel:
All must focus their attention and direct their hearing to listen with reverence, awe, and rejoicing while trembling, as on the day the Torah was given at Sinai... Scripture established it [Hakhel] to strengthen the true faith. One should view himself as though he was instructed now for the first time regarding the Torah, as though he is hearing it now from the Almighty.
Accordingly, Moshe taught Bnei Yisrael about Hakhel specifically at the end of their forty‑year sojourn, as they prepared to enter the Land of Israel. The essence of the mitzvah of Hakhel is that when Bnei Yisrael are in circumstances drastically different from those in which they experienced the great G‑dly revelation at Sinai, they should strengthen their commitment to the Torah by periodically recreating and reliving that Sinai experience. So, as Bnei Yisrael prepared to part from the desert in which they received the Torah, and from Moshe who had taught it to them, they were commanded to recreate the ambiance of the giving of the Torah through Hakhel, in order to strengthen their eternal adherence to the Torah’s commands.
—Likkutei Sichos, vol. 34, pp. 187–190
