Behold, it is explicitly stated in the Torah and [the works of] the
prophets that the Holy One, blessed be He, is not [confined to] a body
or physical form, as [Deuteronomy 4:39] states: "Because God, your
Lord, is the Lord in the heavens above and the earth below," and a
body cannot exist in two places [simultaneously].
Also, [Deuteronomy 4:15] states: "For you did not see any image," and
[Isaiah 40:25] states: "To whom can you liken Me, with whom I will be
equal." Were He [confined to] a body, He would resemble other bodies.
[If so,] what did Moses, our teacher, want to comprehend when he
requested: "Please show me Your glory" [Exodus 33:18]?
He asked to know the truth of the existence of the Holy One, blessed
be He, to the extent that it could be internalized within his mind, as
one knows a particular person whose face he saw and whose image has
been engraved within one's heart. Thus, this person's [identity] is
distinguished within one's mind from [that of] other men. Similarly,
Moses, our teacher, asked that the existence of the Holy One, blessed
be He, be distinguished in his mind from the existence of other
entities, to the extent that he would know the truth of His existence
as it is [in its own right].
He, blessed be He, replied to him that it is not within the potential
of a living man, [a creature of] body and soul, to comprehend this
matter in its entirety. [Nevertheless,] He, blessed be He, revealed to
[Moses] matters which no other man had known before him - nor would
ever know afterward - until he was able to comprehend [enough] from
the truth of His existence, for the Holy One, blessed be He, to be
distinguished in his mind from other entities, as a person is
distinguished from other men when one sees his back and knows the
structure of his body and [the manner in which] he is clothed.
This is alluded to by the verse [Exodus 33:23]: "You shall see My
back, but you shall not see My face."