ואף שבשניהם אור אחד שוה בבחינת הסתר פנים
True, in terms of the "concealment of Countenance" i.e., the degree to which the "Countenance," the inner aspect of the divine life-force, is concealed, the light i.e., the divine creative life-force is the same in both [body and soul] — it is concealed equally in both.
ולבושים שוים שהאור מסתתר ומתעלם ומתלבש בהם
The garments in which the light hides, conceals and clothes itself are identical [in body and soul].
כי שניהם הם מעולם הזה, שבכללותו מסתתר בשוה האור והחיות שמרוח פיו יתברך
For both [body and soul] are of this world where, throughout the world and all its creatures (spiritual as well as physical), the light and life-force issuing from "the breath of [G‑d's] mouth" are equally concealed,
בבחינת הסתר פנים, וירידת המדרגות בהשתלשלות העולמות ממדרגה למדרגה בצמצומים רבים ועצומים
by "concealment of the Countenance," and [by] the descent of the life-force from level to level, by means of numerous powerful tzimtzumim (contractions) through the various levels [constituting] the chain-like succession of worlds,
עד שנתלבש בקליפת נוגה, להחיות כללות עולם הזה החומרי
finally clothing itself in kelipat nogah, in order to give life to the totality of this material world.
The Alter Rebbe has here described the process whereby the divine life-force descends from its lofty, G‑dly origin to the point where it creates and gives life to physical matter; i.e., from "the breath of G‑d's mouth" — a reference to Malchut of the World of Atzilut — to the World of material Asiyah.
He defines various steps in this process: (1) "descent from level to level"; (2) "numerous tzimtzumim"; (3) "powerful tzimtzumim"; (4) "clothing itself in kelipat nogah."
Let us examine them individually:
(1) "Descent from level to level:" To reach down to the level of Asiyah, the life-force must first descend form the World of Atzilut to Beriah, thence to Yetzirah, and finally to Asiyah. Within each of these Worlds there are many levels, and the life-force must descend through them all before reaching the next lowest World.
(2) "Numerous tzimtzumim:" Each descent of the life-force entails a "contraction" of the light and life-force, lessening its intensity.
But descent and tzimtzumim alone, no matter how numerous, will still not make possible the creation of a physical being; the divine life-force would still be at a level where anything created by it would be a spiritual being, albeit of a lower grade of spirituality. The creation of physical matter presupposes another condition, viz.:
(3) "Powerful tzimtzumim:" I.e., tzimtzumim which entirely change the character of the life-force (and not only its intensity), to the point where it can create and give life to material beings. But even this type of tzimtzum cannot produce a world like ours, in which it is not apparent that G‑d is the Creator, and where, in fact, G‑d's creations can be used in defiance of His Will. This is achieved only when —
(4) "The life-force... clothes itself in kelipat nogah" (and thereby also in the other kelipot, as will soon be explained). As defined in the first chapter of Tanya, kelipat nogah is a mixture of good and evil. Therefore, whatever receives its G‑dly life-force through the veil of kelipat nogah (in which the life-force is clothed) can be utilized either for a holy purpose, in serving G‑d's Will through performing a mitzvah, or for an unholy purpose, in violating His Will through a sinful act.
In summary: Through many descents and powerful tzimtzumim, the G‑dly life-force clothes itself in kelipat nogah, and thereby gives life to all the creatures of this world.
The Alter Rebbe now distinguishes between permitted and forbidden objects. The former receive their life-force directly through kelipat nogah; for the latter to receive the G‑dly life-force clothed in kelipat nogah, it must first descend still further, to be veiled in the three completely impure kelipot.
דהיינו כל דברים המותרים והטהורים שבעולם הזה, וממנה ועל ידה מושפעים דברים הטמאים כי היא בחינה ממוצעת, כנ״ל
This means: (1) all things of this world that are permitted and pure which receive their vitality directly via kelipat nogah; and from and through [kelipat nogah] evolve (2) all impure, forbidden things, which derive their vitality from the three impure kelipot; yet their vitality too, stems from nogah since it is the intermediary level between holiness (where all life originates) and the three impure kelipot, as mentioned above.
We can conclude from this that there is no difference between the life-force of the soul and that of the body in terms of revelation or concealment. Since both body and soul are of this world, the life-force in them is equally concealed in the veil of kelipat nogah.
אף על פי כן, ההארה, שהיא המשכת החיות אשר ה׳ מאיר ומחיה דרך לבוש זה
Nevertheless, the [G‑dly] illumination, meaning the flow of vitality by which G‑d illumines and gives life to all creatures of this world by way of this garment i.e., kelipat nogah,
אינה שוה בכולן, בבחינת צמצום והתפשטות
is not the same for them all, and the difference between the life-force of the various creatures is in terms of contraction and expansion. In some creatures the life-force is constricted and limited, while in others it finds broader expression.
The difference between "concealment" (hester) of the life-force and its "contraction" (tzimtzum) can be expressed as follows:
Suppose one hangs a thick curtain on a window to screen out the sunlight. The light entering the room through the curtain will be of an entirely different quality; in fact it might be described as a mere echo of the original light. This is "concealment".
If on the other hand, one boards up the window and leaves only a tiny hole by which the light may pass, the light shining through the hole, though greatly restricted, will be the same, qualitatively, as the original light. This is what is meant by "contraction".
So it is too with regard to our subject: Kelipat nogah is the thick curtain which veils the divine creative power equally from all creatures of this world. This "curtained" light varies, however, from one creature to another in degree of contraction. The Alter Rebbe now goes on to enumerate these differences:
