By Rabbi David Shasho:
וַיְדַבֵּר ×”’ ×ֶל משֶ××” בְּהַר ×¡Ö´×™× Ö·×™ ל×מֺר
Hashem spoke to Moshe on Har Sinai saying…
Rashi asks, “Why does the Torah say specifically by the laws of Shemittah ‘on Har Sinai?’â€
The Imrei Shefer offers an explanation of the connection between shemittah and Har Sinai. Shemittah is called Shabbat, for just as Shabbat is the source of blessing for the other six days of the week, shemittah is the source of blessing for the other six years of the shemittah cycle. If a person allows his fields to lie fallow during shemittah, that is what will bring him success during the years when he eventually works the land.
Har Sinai itself serves as an embodiment of this concept. When Hashem came to give the Torah, all of the mountains presented their credentials, as it were, in the hopes that the Torah would be given on them. Har Sinai, however, was modest and standing at the side and not touting its own qualifications for having the Torah given upon it. That was why Har Sinai merited to become greater than all of the other mountains.
This is the connection between shemittah and Har Sinai, just as Har Sinai‘s inactivity and humbleness was what led to its eventual distinction, our inactivity during shemittah and humble faith resting from work on Shabbat is what leads to our receiving Hashem’s blessing.
Shabbat Shalom