By Rabbi David Cohen:
And Hashem spoke to Moshe on Har Sinai saying. (25:1)
Hashem spoke to Moshe Rabbeinu on Har Sinai concerning the laws of Shemittah, the Sabbatical/seventh year. Rashi asks: Why Shemittah? How is Shemittah linked to Sinai? He explains that the Torah is teaching us that just like Shemittah is detailed with rules and fine points, likewise, this applies to all mitzvot; their rules and details were taught to them at that time as well. The laws of Shemittah were not repeated again prior to the Jews’ entrance into the Land. As such, everything took place at Sinai, with Shemittah serving as the prototype, for all other mitzvot. Is this lesson so vital to our observance of mitzvot that the Torah underscores the fact that the minutiae of details of the mitzvot heralds back to Sinai?
Horav Nissan Alpert, zl, explains that the lesson for us is that we have maintained the same degree of sanctity upon hearing the details of the mitzvah as we had when we heard its general principles. Sometimes we hear a general concept and we agree, accept and are prepared to move forward with execution until we hear the details, the nitty gritty, daily demands. Klal Yisrael did not flinch when they heard the details.
Shabbat Shalom