On Sukkot we are commanded to shake four species: the etrog (citron), which represents the heart, the lulav (palm branch), which represents the spine, hadassim (myrtle leaves), which represent the eyes, and aravot (willow branches), which represent the lips. Rabbi Yaacov Hillel, a great Rabbi and Kabbalist in Jerusalem, explains that Hashem commands us to shake the species as a reminder of what we need to do to be proactive about keeping our slates clean this year: We should guard our eyes and train ourselves to see the good in people and the blessing around us; we should be careful as to what goes into our mouths and what comes out of our mouths, speaking positive, kind words and refraining from speaking loshon hara (gossip); our minds should guide our hearts’ desires, as oppose to our hearts’ desires controlling our minds; and we should have a strong backbone and be true to our values.
Still, why are there so many mitzvot this time of year? We just finished Rosh Hashanah and Yom Kippur and now we have to build sukkahs and shake species? Contrary to popular belief, the judgment of Rosh Hashanah is sealed with finality not on Yom Kippur, but on Hoshanah Rabbah and Shemini Atzeres (this Sunday and Monday, respectively, followed by Simchas Torah on Tuesday). The Nesivos Sholom, a great Chassidic Rebbe from the previous generation, explains that Hashem gives us so many mitzvot this month in order to give us many opportunities for deveikus or attachment to Hashem, which mitigates and even counteracts the harsh force of judgment present during this time. Let’s take advantage of the highly charged mitzvot we can do during this time, starting with Shabbat tonight!
 Rabbi Yaacov Hillel, Ascending Jacob’s Ladder, p.72-73.
 Rabbi S. Binyomin Ginsberg, Gems From The Nesivos Sholom, Yamim Noraim, Foreword by Rabbi Naftali Reich, p. 28-29.