The crops produced during the sixth year will suffice for portions of the three calendar years affected by Shemittah: from Nissan of the sixth year until Nissan of the eighth year. In commentary on this pasuk, Horav Michel Feinstein, zl, explained that Hashem was ensuring the blessing as part and parcel of the mitzvah. The mitzvah itself provided the blessing. This is similar to the statement made by Chazal in Pirkei Avos, Maasros s’yag l’osher, “Tithes are a protective fence for wealth” (Avos 3:17). The discipline of taking a percentage of one’s produce and giving it to charity motivates the owner to realize that all wealth comes from Hashem. He owns it all and gives us the portion which He deems we deserve. When a person understands the true source of all wealth, he becomes worthy of even greater wealth. Thus, the tithing process in and of itself engenders one’s fortune. Likewise, Shemittah observance catalyzes blessing.
This is alluded to by the vernacular of the pasuk, “I will ordain My blessing.” The mitzvah itself will bless the one who observes it. We find a similar instance in Shemos 16:29, “See that Hashem has given you the Shabbos; that is why He gives you, on the sixth day, a two-day portion of bread.” This means that Shabbos observance generates the blessing one will receive.
Veritably, all positive mitzvos generate blessing by virtue of their observance. The following analogy underscores this idea. A young man, who had for years forsaken his religious observance, approached his father with a request. Like all young people, he felt he needed a rest, a vacation from his over-worked life. Alas, it is difficult to enjoy a real vacation without funds. He asked his father for a sizeable sum, so that he could enjoy a “real” vacation. His father, who was as astute as he was loving, countered, “I will be happy to give you ten thousand dollars for your vacation on one condition: that you put on Tefillin for one week. Your Tefillin have been gathering dust in your room since your bar mitzvah. If you are prepared to accede to my request, I will wire the money to you after one week.”
The young man agreed. His father gave him a few hundred dollars to start off and, after one week, he would send the remainder of the money. At end of the first day, the father called up his son and asked, “Nu, did you put on Tefillin today?” “Abba, of course I did” was his son’s reply. The next day, the father once again called his son and asked, “Did you put on Tefillin today?” “For sure!” was his son’s response. Two days later, the father once again called and asked, “Did you put on Tefillin today?” “Why do you not trust me?” the son raised his voice and asserted, “You never believe me. If I said I put on Tefillin today, you can trust me.”
On the seventh day, the son did not wait for his father’s call. He called and reminded his father that the week was up; it was collection time. Could he, please, wire the money to him? “You put on Tefillin every day?” the father asked one last time. “Certainly! If I said I put on Tefillin, you can trust me” was the son’s smug response.
At this point, the father could no longer contain himself. “I was so hopeful that this time, for once, you would be honest with me,” the father began. “What do you mean?” the son asked. “I did my part, now you had better keep your word and pay up.”
“Do you think that I did not know with whom I was dealing? Before you left, I placed the ten thousand dollars inside the Tefillin bag. Had you been putting on Tefillin, you would have surely discovered the money!”
This is the idea behind all mitzvos. When a person performs a mitzvah, the reward is inherent in the mitzvah performance. An observant Jew – by virtue of his observance – is blessed. He just has to “open the bag” to realize that the blessings are to be found within.