At the beginning of the Book Devarim the verse states: “In the fortieth year, on the first day of the eleventh month, Moshe spoke to the Children of Israel regarding all that G‑d had commanded him for them.”1

What, exactly, did Moshe say?

The Seforno explains2 that Moshe repeated all the Torah given up to that time. Indeed, this is one of the reasons why the Book of Devarim is also known as “Mishneh Torah, ” the “Repetition of the Torah.”3

Our Sages note4 that the Book of Devarim differs from the first four Books of the Torah in that the latter are “from G‑d’s mouth,” while Devarim is “from Moshe’s mouth.”

This does not — Heaven forfend — imply that the words in Mishneh Torah are not G‑d’s. Rather, as Rashi explains:5 “Moshe did not say Mishneh Torah to the Jews on his own, but as he would receive it from G‑d he would repeat it to them.”

Since the words of Mishneh Torah too are not Moshe’s words but G‑d’s, why are the first four Books of the Torah considered to be from “G‑d’s mouth” while the Book of Devarim is considered to be from “Moshe’s mouth”; what difference is there between the first four Books and the fifth?

The inherent sanctity of Torah is such that it completely transcends this physical world;6 in order for it to descend within this world an intermediary is necessary — one who is both higher than this world yet within it. This intermediary bridges the gap between the sacred Torah and this corporeal world.

Moshe served as the intermediary, inasmuch as he combined aspects of this world with higher levels. His humility was truly otherworldly; concurrently, he attained the highest degree of completeness possible for an earthly being.7

Information flows through an intermediary in one of two ways:8

a) The information passes through but does not become united with the intermediary; all he does is bring about its descent.

b) The communication becomes so wholly unified with the intermediary that it is refashioned — personalized — by its passage through him. This, in turn, enables the recipients to receive the information according to their own personal levels of intellect.

An example: When intellect is transmitted through one’s fingers, e.g., when one jots down an idea or paints a picture, the fingers do not refashion the thought. However, when a thought is drawn down with emotion, the emotion will color and change the intellect accordingly.9

Herein lies the difference between the first four Books of the Torah and Mishneh Torah : In the first four, Moshe served as a go-between in the first manner, and Torah remained a communication “from G‑d’s mouth,” while in Mishneh Torah His words were clothed within Moshe’s intellect, and are therefore considered to be “from Moshe’s mouth.”10

What is the advantage of having Torah clothed in Moshe’s intellect? Seemingly, this involves a descent in sanctity.

When a flow of divine knowledge is not clothed in the intellect of a human intermediary, it eludes comprehension, for such knowledge is by definition beyond the grasp of the receiver, and the intermediary did nothing to make it more accessible.

Thus, were Torah to have been transmitted only in the manner of the first four Books (i.e. “from G‑d’s mouth”), it would have been impossible for the Jews to truly comprehend it. When Moshe, however, repeated the Torah to them in his own words (i.e. “from Moshe’s mouth”), it became comprehensible.

Based on Likkutei Sichos Vol. XIX, pp. 9-12.