ומביאה ללב שלם כו׳

Moreover, this leads to a “whole heart,” for the latter verse concludes, “and serve Him with a whole heart”; i.e., a knowledge of G‑d leads one to serve Him with one’s entire being.

As explained in Likkutei Torah, in the discourse beginning VeLo Tashbit, this refers to serving G‑d with awe — and this is the ultimate intent of all the mitzvot, as the Torah states,45 “G‑d has commanded us to perform all these statutes so that we may fear the L‑rd our G‑d.” And it is the study of the innermost dimensions of the Torah and a knowledge of the various spiritual levels which comprise the order of Hishtalshelut that enable one to fulfill the mitzvah of “knowing G‑d,” which leads in turn to the “whole heart” of “fearing Him.” Thus the Alter Rebbe concludes:

שהוא העיקר

And this is the essential thing: the wholehearted awe of G‑d is the ultimate purpose of all the commandments.

As mentioned above, one can attain this state only through a knowledge of the order of Hishtalshelut, even though this knowledge is merely an awareness of its existence and not a grasp of its essence.

והשגת המציאות הוא להפשיט מגשמיות כו׳

The comprehension of existence entails divesting [this subject] of any physicality….

In other words, one should endeavor to picture its spirituality. Hence, as the Rebbe has often stressed, one should study the innermost and mystical dimension of the Torah in such a way that one46 “derives sustenance from it” (יתפרנסון מיניה) — viz., the “sustenance” derived from comprehension. And soundly-based comprehension can be secured only when this dimension of the Torah is studied with the intellectual elucidation afforded by the teachings of Chabad.

רק שזו היא מצוה אחת מתרי״ג

However, this mitzvah (of knowing G‑d and apprehending Divinity) is but one mitzvah of the 613,

והאדם צריך לקיים כל תרי״ג

and a man must fulfill all 613,

לפי שהן השתלשלות המהות דחיצוניות דכלים דאצילות

for they descend from the essence of the external aspect of the vessels of Atzilut, a source whose standing was explained above.

לכך צריך להרבות בלימוד כל התרי״ג, וקיומן בפועל ממש, במחשבה דבור ומעשה, שהן בריאה, יצירה, עשיה

Hence, one must extensively study all 613 mitzvot, and [hence] fulfill them in actual practice in thought, speech and deed — which parallel Beriah, Yetzirah and Asiyah respectively —

לברר בירורין אשר שם

in order to purify whatever needs purification (beirur) there.

As previously explained, the extraction and elevation of the sparks exiled in the various worlds is the ultimate purpose of creation.