Even more significant is the paradox of the fifth book of the Torah, the book of Deuteronomy. In a series of essays,1 the Rebbe explores the unique characteristics of the book of Deuteronomy and its place in the divine communication of Torah.

The Talmud and Zohar differentiate between the first four books of the Torah and the fifth book, stating that the first four were transmitted by Moses “from the mouth of the Almighty,” whereas the book of Deuteronomy was spoken by Moses “from his own mouth.”2 Indeed, many of the Both the divine and the human aspects of Torah attain full expression, without obscuring each othercommentaries note that first four books of the Torah are written in the third person (e.g., “G‑d spoke to Moses, saying…”), whereas in the book of Deuteronomy we hear Moses’ voice in first person (“At that time G‑d said to me…,” etc.).3

Yet the book of Deuteronomy is part and parcel of the Written Torah, whose every word and letter are considered to be of divine origin.4 Various explanations are given by the commentaries to resolve this contradiction, the crux of which is that while the divine communications contained in the book of Deuteronomy were “processed” through the mind and speech of Moses, these very words and letters constitute the unadulterated word of G‑d.5 Rabbi Schneur Zalman of Liadi explains that this was possible due to degree of bitul which Moses achieved. Moses had so totally abnegated his ego to the divine will that “the divine presence spoke from his throat”—Moses’ own words are also G‑d’s own words.6

Thus, says the Rebbe, the book of Deuteronomy acts as a bridge between the Written Torah and the Oral Torah. In the first four books of the Written Torah, the divine element dominates, in that its every aspect, from the core principle to the specific formulation of the words, is manifestly divine; here, the human contribution is limited to the fact that a human soul and mind served as the channel through which the communication passed, essentially unchanged. In the Oral Torah, the reverse is the case: the human contribution is most pronounced, while the divine aspect is manifested primarily in the concepts and principles which drive the human intellect’s arguments and formulations. But in the book of Deuteronomy, both the divine and the human aspects of Torah attain full expression, each without obscuring the other. The divine idea is processed by the mind of Moses, so that it emerges as Moses’ own words; yet such is Moses’ identification with the divine wisdom and will that his own words are completely in harmony with their divine essence—so much so, that they are no less G‑d’s words than the words which G‑d dictated in the first four books.

The Rebbe concludes:

Based on all of the above, we can say that the reason that it was necessary that within the Written Torah there should be such a phenomenon—i.e., that the revelation of the divine words should come about in such a way that they were first processed in the mind and intellect of Moses—is because this is the foundation and precedent for the phenomenon of the “Oral Torah.”

This is because in there is a fundamental paradox in the very nature and definition of the Oral Torah. On the one hand, the Oral Torah (with the exception of those laws revealed to Moses at Sinai and handed down by tradition) is revealed by the people of Israel through their study of Torah, in a process that enlists the intellect and understanding of the Torah scholar. On the other hand, the entire purpose of Torah learning is to reveal the word of G‑d. The resultant ruling is not a product of human logic, but of the divine will. For Torah, in essence, is the divine wisdom; it is only that G‑d gave it to the people of Israel that they should reveal it through their study and understanding.

And since everything about Torah is rooted in the Written Torah, this too—i.e., the fact that ideas generated by the mind and intellect of a mortal human being should be deemed “Torah” and divine instruction—must exist within the Written Torah. Hence the Written Torah includes the book of Deuteronomy, which incorporates both extremes, being the word of G‑d as it is processed by the mind and intellect of Moses. By virtue of this precedent being part of the Five Books of Moses, it then extends, more broadly, to the Oral Torah as a whole.7