כי מקור החיות הוא רוח פיו של הקב״ה, המתלבש בעשרה מאמרות שבתורה

For the source of the life-force is the “breath of the mouth” of the Holy One, blessed be He; it becomes enclothed in the Ten Utterances of the Torah, from which all created beings come into existence.

ורוח פיו יתברך היה יכול להתפשט לאין קץ ותכלית, ולברוא עולמות אין קץ ותכלית לכמותם ואיכותם, ולהחיותם עדי עד

The “breath of His mouth” could have diffused without end and limit, and created worlds infinite in their quantity and quality, and given [them] life forever, unlike their present state, in which they are limited in all these respects,

ולא היה נברא עולם הזה כלל

and this corporeal world, all of whose beings are limited and finite, would not have been created at all.

It was the contraction of the life-force that made possible the creation of this physical, limited world with its finite creatures.

The reason why the “breath of His mouth” — were it not to have been contracted — would have created worlds without end, is now explained by the Alter Rebbe in the parenthesis.

שכמו שהקב״ה נקרא אין סוף, כך כל מדותיו ופעולותיו, דאיהו וגרמוהי חד

(For just as the Holy One, blessed be He, is called “Infinite”, so are all His attributes and actions [infinite], “for He and His attributes are one”;

דהיינו החיות הנמשך ממדותיו, שהן חסד ורחמים ושאר מדותיו הקדושות, על ידי התלבשותן שמתלבשות ברוח פיו

i.e., the life-force that emanates from His attributes, namely, Kindness and Mercy and His other holy attributes, [emanates from them] through their being enclothed in the “breath of His mouth,” which refers to the Sefirah of Malchut.

כי הוא אמר ויהי

For creation results from G‑d’s speech and the “breath of His mouth,” as Scripture states,1 “For He spoke — and it came into being.”

ועולם על ידי חסד יבנה

Moreover, creation came about through Chesed, as it is written,2 “The world is built through Chesed,

But how is it that the world is created both through Chesed and Malchut (the “word of G‑d”)? This means: the attribute of Chesed vests itself within Malchut,

בדבר ה׳ ורוח פיו, הנעשה כלי ולבוש לחסד זה

so that creation takes place through “the word of G‑d and the breath of His mouth,” which becomes a vessel and “garment” for this creative attribute of Chesed,3

כהדין קמצא דלבושיה מיניה וביה

“like the snail, whose garment is an integral component of his body.”)

The “word of His mouth” is thus a garment and vessel that unites with the attribute of Chesed, from which the world was created. The life-force emanating from the “breath of His mouth” is thus capable of creating worlds which are infinite both quantitatively and qualitatively.

אלא שצמצם הקב״ה האור והחיות שיוכל להתפשט מרוח פיו

The Holy One, blessed be He, however, contracted the light and life-force that could diffuse from the “breath of His mouth,”

והלבישו תוך צירופי אותיות של עשרה מאמרות וצירופי צירופיהן

and invested it in the combinations of the letters of the Ten Utterances, and the combinations of their combinations,

בחילופי ותמורות האותיות עצמן, ובחשבונן ומספרן

by substitutions and transpositions of the letters themselves and their numerical values and equivalents.

שכל חילוף ותמורה מורה על ירידת האור והחיות ממדרגה למדרגה

For each substitution and transposition indicates the descent of the light and life-force degree by degree,

דהיינו שיוכל לברוא ולהחיות ברואים, שמדרגת איכותם ומעלתם היא פחותה ממדרגת איכות ומעלת הברואים הנבראים מאותיות ותיבות עצמן שבעשרה מאמרות

so that it will be able to create and give life to creatures whose quality and significance is lower than the quality and significance of the creatures created from the very letters and words of the Ten Utterances

שבהן מתלבש הקב״ה בכבודו ובעצמו, שהן מדותיו

within which is enclothed the Holy One, blessed be He, in His Glory and Essence — which are His attributes, since they are one with G‑d Himself.