והנה צמצום זה היא סבת ההארה שמאירות שם חב״ד של אין סוף ברוך הוא לנשמות אלו בעולם הבריאה
This contraction (which ChaBaD of Atzilut undergo in order to radiate in Beriah) thus causes the souls in the World of Beriah to be illuminated by a glow of ChaBaD of Ein Sof (i.e., ChaBaD of Atzilut); it is this contraction that enables them to have some perception of the Ein Sof-light.
מה שאין כן באצילות, שאינם בבחינת צמצום כל כך, אי אפשר לשכלים נבראים לקבל מהן
The created intellectual beings [of Beriah] cannot, however, apprehend ChaBaD as they are (i.e., in all their undimmed intensity) in the World of Atzilut, where the ChaBaD are not contracted to such a great degree as in Beriah.
"To such a great degree" — for the very fact of their being Sefirot (i.e., individual, defined categories) indicates that ChaBaD are merely contracted, limited manifestations of the undefinable Ein Sof; the degree of contraction, however, is much less than that of Beriah, and therefore the creatures of Beriah cannot receive intellectual illumination from ChaBaD of Atzilut.
ולכן לית מחשבה דלהון תפיסא שם כלל
Therefore, their thought cannot grasp there at all, i.e., the thought and intellect of the created beings of Beriah can in no way grasp the light radiating in Atzilut.
לכן הוא מדור לצדיקים הגדולים
For this reason, [Atzilut] is the abode of the great tzaddikim,
שעבודתם היא למעלה מעלה אפילו מבחינת דחילו ורחימו הנמשכות מהבינה ודעת בגדולתו יתברך
whose service of G‑d is far superior even to fear and love derived from understanding and knowing His greatness,
כמו שעולם האצילות הוא למעלה מעלה מבחינת בינה ודעת לשכל נברא
just as Atzilut transcends by far the level of the understanding and knowledge of a created being's intellect.
אלא עבודתם היתה בבחינת מרכבה ממש לאין סוף ברוך הוא
Their service is, rather, on the level of an actual "chariot" of the blessed Ein Sof,
וליבטל אליו במציאות, ולהכלל באורו יתברך, הם וכל אשר להם
nullifying their very existence before Him, and incorporating themselves, and all that they possess, within His light,
על ידי קיום התורה והמצות
through the observance of the Torah and the mitzvot.
על דרך שאמרו: האבות הן הן המרכבה, והיינו לפי שכל ימיהם היתה זאת עבודתם
Our Sages applied such a description to the Patriarchs, saying that1 "they themselves constituted the divine chariot," for this was the Patriarchs' level of service, throughout their lives.
The Patriarchs were constantly in that state of self-nullification before G‑d denoted by the term "chariot". Similarly, in the case of the tzaddikim spoken of here. Through their Torah and mitzvot, they effect the highest degree of self-nullification before G‑d in themselves and in all their affairs. The abode of their souls, therefore, is likewise in a World pervaded with this spirit of self-nullification, namely the World of Atzilut.
