Among the Torah commandments of the festival of Sukkos are the commands to dwell seven days in a sukkah and to take the “four kinds,” the esrog, lulav, hadassim and aravos (the citron, palm-branch, myrtle and willow).

The latter commandment is not actually considered a distinct act to be performed during the seven days of Sukkos. Rather, the taking of the “four kinds” is related to the mitzvah of sukkah itself;1 this also being the reason for the assertion that the best way of performing the mitzvah of the “four kinds” is within the sukkah.2

The sukkah encompasses a Jew and all his possessions with holiness. The taking of the “four kinds” has the additional benefit of drawing down this degree of G‑dliness into the Jew — “You shall take unto yourselves a citron.”

Indeed, this is why the “four kinds” are placed near the heart,3 so that their effect will be felt within the heart, the seat of human emotions. From the heart, all the other bodily organs, including the intellect, are infused.

In terms of man’s spiritual service, the encompassing quality of the sukkah reflects the transcendental quality of mesirus nefesh, total self-sacrifice for the sake of G‑d — a level that surpasses all human powers, while taking the “four kinds” points to the individual’s finite powers of intellect, emotion, etc.

This being so, it would seem that drawing down the infinite encompassing level of the sukkah into the finite sense of self via the “four kinds” would be a step backward, from the infinite to the finite. Why, then, are we commanded to take the “four kinds” in order to draw down — and seemingly limit — this infinite level of sukkah?

The reason is that complete mesirus nefesh only results when the attendant state of self-nullification permeates a person’s intellect and emotions, so that they too desire this exalted state.

There are two reasons why this is so:

a) Only when mesirus nefesh permeates the entire individual can it become a permanent part of his self;

b) when all aspects of a person are permeated with mesirus nefesh, the true power and scope of mesirus nefesh is thereby demonstrated; every point within the individual has become permeated by its power.

The above helps clarify yet another matter: The festival of Sukkos is to be celebrated with joy, for it is one of the three pilgrim festivals — Pesach, Shavuos and Sukkos — concerning which G‑d commands us: “You shall rejoice in your festival....”4 This is particularly so since Sukkos is referred to in the holiday prayers as the “Season of Our Joy.”

The particular mitzvah of Sukkos which the Torah associates with joy is the taking of the “four kinds,” concerning which the verse states:5 “On the first day you shall take unto yourselves a citron... and you shall rejoice before the L‑rd your G‑d for seven days.”6

Why is the taking of the “four kinds” singled out for its connection to rejoicing, and not the commandment to dwell in a sukkah? In light of the explanation given above, the reason becomes obvious:

If the full state of mesirus nefesh is realized specifically when it permeates a person’s inner powers, then this is surely so with regard to joy, for true joy must actually be felt inwardly. At the same time true joy is not subject to one’s inward limitations.

True joy results when the encompassing level of the sukkah is drawn down by the taking of the “four kinds” — “you shall take unto yourselves ... and you shall rejoice.”

Based on Likkutei Sichos, Vol. XXIV, pp. 246-250.