The Sukkah: Feeling at Home Amidst G-dliness
Adapted from Likkutei Sichos, Vol. II, Sukkos; Vol. XIX, Sukkos
To be Surrounded by a Mitzvah
The Torah commands,  "For seven days you shall dwell in sukkos."
In defining this mitzvah, our Sages state,  "You must live [in the sukkah] just as you live [in your home]."
For the seven days of the holiday,  all of the daily routines of our life must be carried out in the sukkah. As our Sages explain:  "For all of these seven days, one should consider the sukkah as one's permanent dwelling, and one's home as temporary.... A person should eat, drink, relax... and study in the sukkah."
Our Sages point out that  "the mitzvos were given for the sole purpose of refining the created beings": by observing a mitzvah a person elevates himself and his surrounding environment.
Most mitzvos are focused only on limited aspects of our being and limited dimensions of our environment. When putting on tefillin one elevates one's head, heart,  and arm, as well as the actual leather artifacts involved. When, by contrast, a person lives in a sukkah, his entire body is enveloped by the mitzvah: even the most mundane aspects of his life become means of connection  to G-d.
The message of the mitzvah of sukkah is not self-contained; it influences our conduct throughout the entire year to come.
The Torah simply tells us to  "know Him in all your ways"; and our Sages comment,  "This is a short verse upon which all the fundamentals of the Torah depend."
For, G-dliness is present not merely in the synagogue or in the house of study, but in every dimension and corner of our lives. This concept is made tangible by the mitzvah of dwelling in a sukkah.
Infusing Spirituality into Our Material World
Whenever one fulfills a mitzvah with material objects, a connection is established between them and the spiritual import of the mitzvah.  From that time on, they are known as tashmishei mitzvah ("objects used for a mitzvah"). Since their connection with spirituality remains, an object that has been used in performing a mitzvah should not later be used for unrefined purposes. 
There is an even deeper connection between the building materials used for the sukkah and the spiritual influences associated with it. Thus our Sages say,  "Just as the sacrifices become consecrated for the sake of heaven,... so too, the sukkah becomes consecrated for the sake of heaven." 
The sukkah represents a deeper fusion between materiality and spirituality than that which is achieved through the performance of many other mitzvos.
In most instances, the connection between the material object and the spiritual effect established through the observance of a mitzvah does not permeate the material entity entirely.
Therefore, though we are required to treat them with respect, these objects are not considered holy: they are not totally united with spirituality.
Consecration implies that the physical entity becomes suffused with holiness, and this deeper bond is achieved through the mitzvah of dwelling in the sukkah.
"Your Sukkah of Peace"
Our Sages associate the mitzvah of sukkah with unity, as may be seen by the phrase,  "Your sukkah of peace," and in our Sages' statement that  "All Israel are fit to dwell in one sukkah."
Why is the sukkah associated with peace and unity?
Chassidic thought  explains that observing the mitzvah of sukkah draws down to this world a transcendent spiritual light whose revelation erases all differences between individuals and establishes a fundamental equality among them.
Our world is characterized by differentiation.
The mitzvah of sukkah is intended to suffuse the world with a G-dly state of oneness that is, essentially, uncharacteristic of this diverse world.
In another sense, the unity established by this mitzvah resolves the differences that exist between spirituality and material existence.
From the perspective of the world, the two appear to be opposites. From G-d's perspective, however, both the material and the spiritual are expressions of Himself and can be fused together harmoniously.
The Ultimate Sukkah
Our Rabbis  explain that through dwelling in the sukkah we will merit the rebuilding of the Beis HaMikdash, as is implied by the verse,  "And His sukkah will be in [Jeru]salem." The ultimate fusion between the material and the spiritual will take place in the Era of the Redemption and in particular, in the Beis HaMikdash, where the Divine Presence will be openly revealed.
May this take place in the immediate future.
- (Back to text) Vayikra 23:42.
- (Back to text) Sukkah 28b.
- (Back to text) In the Diaspora we are required to dwell in the sukkah on
Shemini Atzeres as well, though a blessing is not recited
when observing this mitzvah.
- (Back to text) Sukkah, loc. cit.
- (Back to text) Bereishis Rabbah 44:1.
- (Back to text) The tefillin are placed on the head and on the biceps of
the left arm facing the heart.
- (Back to text) The Hebrew word mitzvah ("commandment") is related to the
Hebrew/Aramaic word tzavta ("connection"). By observing a
mitzvah, one establishes a connection with the One who
gave the command. See Likkutei Torah, Parshas Bechukosai 45c.
- (Back to text) Mishlei 3:6.
- (Back to text) Berachos 63b.
- (Back to text) See the essay entitled "What Happened at Sinai?"
- (Back to text) Cf. Megillah 26b; Shulchan Aruch, Orach Chayim 21:1.
- (Back to text) Sukkah 9a, quoted in Shulchan Aruch HaRav 638:1.
- (Back to text) For this reason we are forbidden to use the building
materials of the sukkah for mundane purposes during the
holiday (Shulchan Aruch HaRav 638:15-16).
- (Back to text) Daily liturgy.
- (Back to text) Sukkah 27b.
- (Back to text) See the series of discourses entitled VeKachah 5637, chs. 95-96.
- (Back to text) Maharsha, commenting on Pesachim 5a. See also the Targum
and Midrash Tehillim to Tehillim 76:3.
- (Back to text) Tehillim 76:3.