והנה ה׳ ניצב עליו, ומלא כל הארץ כבודו, ומביט עליו

“And, behold, G‑d [Himself] stands over him,”1 and “The whole world is full only with His Glory,” and not only being omnipresent does He see everything, but moreover He scrutinizes him in particular,

ובוחן כליות ולב אם עובדו כראוי

and searches his reins and heart i.e., his innermost thoughts and emotions [to see] if he is serving Him as is fitting.

ועל כן צריך לעבוד לפניו באימה וביראה כעומד לפני המלך

Therefore, he must serve in His Presence with awe and fear (i.e., notes the Rebbe, not merely like one who is located in the King’s domain, but moreover) like one standing before the King.

ויעמיק במחשבה זו, ויאריך בה כפי יכולת השגת מוחו ומחשבתו, וכפי הפנאי שלו

One must meditate profoundly and at length on this concept, according to the capacity of apprehension of his brain and thought, and the time available to devote to this contemplation; this time being:

לפני עסק התורה או המצוה, כמו לפני לבישת טלית ותפילין

before he engages in [the study of] Torah or [the performance of] a commandment, such as before putting on his tallit or tefillin.

This meditation will enable him to then serve G‑d with awe.

The Alter Rebbe now goes on to explain another form of meditation. Unlike the above thoughts which should preface divine service in general, this meditation relates to the particular mitzvah that the individual is about to perform — to the content of this mitzvah, its distinctive effect, and its influence on his soul.