The Four Species / The Araba'ah Minim Torah & Good Deeds Head, Heart, Hand & Backbone

(40) On the first day you shall take the (1) product of hadar trees, (2) branches of palm trees, (3) boughs of leafy trees, and (4) willows of the brook, and you shall rejoice before the Eternal your God seven days.

[The four species are likened to different categories in the Jewish people.]

• Just as an citron/etrog has both taste and smell, so too is Israel - there are among them people who study Torah and who do good deeds.
• The palm branch/tamar, these are Israel. Just as this palm has taste, but no smell, so too is Israel - there are some among them who do Torah study, but do not do good deeds.
• The myrtle/hadas, this is Israel. Just as myrtle has smell but no taste, so to Israel - there are some among them who do good deeds, but do not study Torah.
• The willow/aravah, this is Israel. Just as this willow has neither taste nor smell, so too they are Israel - there are some people among them who do not do Torah study nor do good deeds.

And what does the Holy Bountiful One do to them? It is impossible to destroy them, but rather the Holy Bountiful One says: Let them be all bound together in one bundle, and they will atone one for the other [or more literally, they will cover for each other.]

And there is also another matter with these four things - that they are similar to precious limbs in a human (see Vayikra Rabbah 30:14; Midrash Tanchuma, Emor 19):

• As the citron/etrog is similar to the heart, which is the dwelling place of the intellect, to hint that one should serve their creator with their intellect;
• the lulav/palm is similar to the backbone, which is the essence of a person, to hint that they should straighten himself completely for God's service;
• the myrtle/hadas [leaves are] similar to the eyes, to hint that one should not stray after their eyes 'on the day of the rejoicing of his heart';
• and the willow/aravot [leaves are] similar to the lips, with which a human completes all of their acts of speech, to hint that one should put a muzzle to one's mouth, calibrate one's words and be in awe of God even at a time of joy.

And the reason that it is only practiced one day in the country (outside of the Temple) is well-known - since the main joy is on the first day [of Sukkot]....And I have come to believe that the kabbalists (mystics) have wonderful secrets about the commandment of the lulav and the three [other plants].