This coming Tuesday, 18 Tishrei, is the 18th yahrtzeit of HaRav Naftali Neuberger, zt"l, of Ner Yisroel.
This shtikle is dedicated le'iluy nishmaso, Naftali ben Meir Halevi.
I heard the following from Rav Tzvi Mordechai Feldheim of Mesivta Kesser Torah last year:
The four species we traditionally take and shake on Sukkos carry numerous different symbolisms. If you ask your typical student, perhaps the most well-known is the midrash (Tanchuma Emor 19) comparing each item to a part of the body. The one lulav is compared to the spine. The one esrog resembles our heart. We take two aravos whose leaves are shaped like lips – of which, of course, we have two. The leaves of the hadas resemble the eyes. Why, then, do we take three, rather than two?
Another oddity regarding the hadas is observed in the discussion in the gemara (Sukkah 32b) regarding configurations of the leaves that render a hadas invalid. The stem should have three leaves coming out together at the same level. If one of the leaves is offset from the other two, although Rav Acha would consider this a virtue, Mar bar Ameimar declared that his father would refer to such a branch as a hadas shoteh – literally, a crazy myrtle. Why is this adjective used for the hadas? We don't find any other invalid mitzvah objects being referred to as shoteh.
We commonly associate the work sukkah etymologically with the schach, the covering, to which many of the intricate halachic details apply. Rabbeinu Bachye (Devarim 16:14), however, suggests that the word is derived from socheh, to see (as in Rashi to Bereishis 11:29). More specifically, it refers to the more abstract vision of wisdom and insight.
Rabbi Feldheim explains that the theme of the sukkah demands of us to let go of our pursuit of material possessions and leave our home in favour of a flimsy hut to remind us of that which is fleeting and meaningless and focus our attention to serving HaShem, the true purpose of our existence. This is the vision to which Rabbeinu Bachye refers that this mitzvah makes so clear. In addition to our two physical eyes, we must possess the third eye to realize this vision. That is why we take three hadasim. As well, the branch with only two leaves aligned is referred to as shoteh because symbolically, it represents the individual who sees only with his eyes and lacks the awareness to understand his true purpose.
Have a good Shabbos and chag samei'ach!