Parashat Emor discusses the various holidays of the Jewish calendar. It is interesting to note that while most holidays are associated with special Mitzvot, Shavuot is bereft of such Mitzvot. Pesach contains the Mitzvot of eating Matzah and recounting the story of Yetziat Mitzrayim, and Sukkot is associated with the Mitzvot of living in the Sukkah and taking the Lulav. No similar commandments exist on Shavuot. What is the reason for this lack of special Mitzvot on the day of Kabbalat HaTorah?
It is possible to suggest that in fact there is a Mitzvah of sorts on Shavuot, albeit an implicit one. On Pesach, we eat Matzah as a remembrance of being slaves in Egypt and being miraculously redeemed. By eating the bread of affliction, we recognize that the redemption was incomplete; we still did not have the Torah. On Shavuot, we finally completed the Geulah from Mitzrayim. In a sense, eating Chameitz on Shavuot is a completion of the Mitzvah of eating Matzah on Pesach, for it represents the conclusion of the remembrance of Geulah begun on Pesach. It is for this reason that the Korban HaOmer brought on Pesach does not contain Chameitz, while the Shtei HaLechem brought on Shavuot does. The Pesach experience peaks on Shavuot with Kabbalat HaTorah.
Rav Dovid Tzvi Hoffman gives an alternative answer to this difficulty. He suggests that because Shavuot is the day of Kabbalat HaTorah, the one Mitzvah we should have on Shavuot is to learn Torah. However, if Hashem had commanded us to learn Torah specifically on Shavuot, one could have mistakenly come up with the notion that he has to learn Torah only on Shavuot and not at any other time during the year. To preclude this misconception, Hashem did not mandate a specific Mitzvah of learning Torah on Shavuot. By contrast, Sukkot is the only time of the year that Jews must remember that they lived in tents while in the Midbar for forty years, and having this specific Mitzvah does not undermine any Mitzvah performance during the rest of the year.
An additional difficulty regarding Shavuot is why the Torah does not specify the precise date on which Shavuot should be celebrated. After all, every other holiday listed in the Torah is given an exact day and month on which to be observed. Perhaps one could answer this question using Rav Hoffman’s idea. If Hashem had told us the exact day of Matan Torah, one could have misunderstood that only on that day must one remember and learn Torah. This is patently untrue (see Rashi to Shemot 19:1 s.v. BaYom HaZeh). By not telling us the exact day of the giving of the Torah, Hashem showed us the importance of learning, not merely on the day of Kabbalat HaTorah, but all the time.