וכל ניצוץ לא ירד לעולם הזה
Each spark did not descend into this world to perfect itself but to perfect the body and vital soul — as the Alter Rebbe will soon conclude.
Having touched upon the subject of the soul's descent, however, he adds a parenthetical comment emphasizing the magnitude of this descent. On entering this world, a soul may perhaps attain the loftiest heights of love and fear of G‑d that are experienced by a perfect tzaddik — but even this cannot compare to the love and fear that it experienced while in the spiritual worlds, before its descent.
אף שהיא ירידה גדולה, ובחינת גלות ממש
Though it is indeed a great descent, a veritable exile for the soul;
כי גם שיהיה צדיק גמור, עובד ה׳ ביראה ואהבה רבה בתענוגים
for even if it become, in this world, a perfect tzaddik, serving G‑d with fear and abundant love of delights,
לא יגיע למעלות דביקותו בה׳ בדחילו ורחימו בטרם ירידתו לעולם הזה החומרי, לא מינה ולא מקצתה
it will not attain to the quality of its attachment to G‑d with fear and love that the soul experienced prior to its descent into this corporeal world, nor even [to] a fraction of [its earlier fear and love].
ואין ערך ודמיון ביניהם כלל, כנודע לכל משכיל, שהגוף אינו יכול לסבול כו׳
In fact, there is no comparison or similarity whatever between them — between the love and fear of G‑d experienced by a soul on earth, and that of the soul above; [for] as is obvious to every intelligent man, the body could not bear etc. a love and fear of such intensity as the soul experienced above, in the spiritual realms.
Having concluded his comment on the formidable nature of the soul's descent, the Alter Rebbe returns to his original point: The descent of the soul is thus undertaken not for its own sake —
אלא ירידתו לעולם הזה, להתלבש בגוף ונפש החיונית, הוא כדי לתקנם בלבד
but its descent into this world, to be clothed in a body and vital soul, is for the sole purpose of perfecting them;
ולהפרידם מהרע של שלש קליפות הטמאות על ידי שמירת שס״ה לא תעשה וענפיהן
to separate them from the evil of the three impure kelipot, by observing the 365 prohibitions and their "offshoots" i.e., by observing the Biblical and Rabbinic prohibitions,
ולהעלות נפשו החיונית, עם חלקה השייך לה מכללות עולם הזה
and to elevate his vital soul, together with the portion of the world at large that belongs to it,
ולקשרם ולייחדם באור אין סוף ברוך הוא אשר ימשיך בהם על ידי קיומו כל רמ״ח מצות עשה בנפשו החיונית
binding and uniting them with the Ein Sof-light which he draws into them by performing all the 248 positive mitzvot through the agency of the vital soul,
שהיא היא המקיימת כל מצות מעשיות כנ״ל
since [the vital soul] is the one that performs all mitzvot involving action, as explained above, in ch. 36 — that the divine soul can activate the body in performance of the mitzvot only by way of the vital soul.
וכמו שכתוב בע׳ חיים, שער כ״ו כי הנשמה עצמה אינה צריכה תיקון כלל כו׳
It is likewise written (in Etz Chayim, Portal 26) that the [divine] soul itself does not need perfecting at all...;
ולא הוצרכה להתלבש בעולם הזה וכו׳ רק להמשיך אור לתקנם כו׳
and there is no need for it to be embodied in this world, in a body and vital soul... except to draw down light to perfect them — the vital soul and the body...
והוא ממש דוגמת סוד גלות השכינה לברר ניצוצין וכו׳
and this parallels exactly1 the mystery of "the exile of the Shechinah," whose purpose is to refine the sparks of holiness which fell into the kelipot; so too does the divine soul enter into exile within the body and vital soul in order to perfect them, and to extract from them the sparks of holiness which they contain.
The foregoing discussion enables us to understand the particular virtue of mitzvot performed through action:
Creation, and the soul's descent into the body, were both intended for the purpose of elevating the body and vital soul, and thereby the entire world; moreover, this objective is reached primarily through the mitzvot involving action, inasmuch as these mitzvot are performed by the body and vital soul; these mitzvot are therefore of primary importance.
