The Torah reading of Behar begins with:1 “G‑d spoke to Moshe on Mount Sinai.” It then goes on to provide a detailed account of the laws of Shemittah, the Sabbatical year.

Rashi , quoting Toras Kohanim asks:2 “What has Shemittah to do with Mount Sinai; [were not] all the commandments given on Sinai?” He answers: “Just as the general, specific, and most minutely detailed laws were related at Sinai, so too, all [the mitzvos] were related, generally, specifically and most minutely.”

In order for a mitzvah to be properly performed, there has to be specific and minutely detailed laws; only when one knows exactly how one is to perform a particular mitzvah will he be able to perform it in the desired manner.

It is easy to see that the “general” laws of all mitzvos were transmitted at Sinai, when G‑d gave Torah and mitzvos to the Jewish people. In fact, the Torah explicitly states this in a number of places, such as:3 “These are the commandments that G‑d gave Moshe for the Jews at Mount Sinai.”

However, one may err in thinking that the detailed laws of only those mitzvos that were to be performed immediately, such as the Ten Commandments and laws establishing social justice, were conveyed at that time, while the details of the rest of the commandments — laws such as Shemittah , which only became germane 20 years after the Jews entered Israel — were communicated at a later date. Rashi therefore explains that the particulars of all the mitzvos were imparted at Sinai.

But why did G‑d relate everything at Sinai, even the details of those mitzvos that would not be applicable until much later? Why not convey these particulars closer to the time when they would become relevant?

When G‑d issues a command, it is of course necessary that the individual so commanded be told precisely how to go about performing the mitzvah; the general laws simply do not suffice.

Thus, it can be seen that the general principles of a mitzvah rely not so much on the person performing it as on the fact that it is G‑d’s command. The particulars, on the other hand, emphasize the person’s performance.

As such, the general commandments place greater emphasis on the Commander, while the particulars involve aspects of the person performing the commandment, and the world and worldly matters in which and with which the mitzvah is performed.

When G‑d gave the Torah and mitzvos at Sinai, He did so to the accompaniment of “thunder and lightning,”4 with the mountain “smoking because G‑d descended upon it with fire”5 — a degree of revelation unparalleled in the annals of history.

If at that time, G‑d would have revealed only the general principles but not the details of all the commandments, the nation could have mistakenly assumed that the general principles, indicative as they are of the Commander of the mitzvos , were of greatest import, while the details were of secondary importance.

By providing all the particulars at the time of this great revelation, G‑d indicated that these details relate directly to the Commander of the mitzvos Himself, and are an integral part of His divine will.

Moreover, revealing all the minute details of the mitzvos involving physical objects during the experience of Sinai also indicated that G‑d desired not merely that His will be performed, but also that by their performance, the physical world itself would become permeated with the spirit of Sinai.

Based on Sefer HaSichos 5748, Vol. II, pp. 455-459