Sefer Bamidbar ends with the pasuk: "These are the laws and the statutes that Hashem commanded Moshe to Bnei Yisrael..." We might have thought that at this juncture, with Bnei Yisrael about to enter Eretz Yisrael, the Torah would be complete. However, the Lawgiver gave us an "additional" chumash, Sefer Devarim, during the last month of the last year in the desert.
Sefer Devarim includes Moshe’s "parting speech," a review of many of the Torah’s laws, and additional mitzvot. We refer to it as "mishneh Torah" (whose possible explanations include review and addition). Moshe speaks in the sefer in the first person, in contrast to the manner that exists in the rest of the Torah. As we know that this sefer is Divinely given just as the others, we wonder why it was presented in a different manner.
The Sifrei (Devarim 1) says that the term "hadevarim asher diber Moshe" indicates that they contain Moshe’s rebuke. The Midrash Tannaim (Devarim 1:1) says on these words that Moshe’s rebuke was dear to Hashem like the Ten Commandments (both are referred to as "devarim"). R. Yishmael (ibid.) points out that in some ways Moshe’s rebuke was more powerful. Soon after Bnei Yisrael received the Ten Commandments, they sinned with the Golden Calf, whereas Moshe’s words kept Bnei Yisrael in a state of clinging to Hashem for a long time. For that reason Moshe was honored to have the words recorded in his name.
Let us explain as follows. The Torah is not a history of mankind or the Jewish People but the story of Hashem’s revelation to the world. Bereishit teaches that Hashem created the world and revealed Himself to our forefathers as individuals. The next sefarim teach that Hashem’s Presence dwelled on a nation, whom He redeemed from Egypt to give the Torah.
How do we know that the events at Sinai have a continuation, that we can accept the Torah in every generation, and that the continuing connection through the prophets strengthens the bond? It is Devarim that connects between that which is presented as classic Torah from Hashem and the Torah that is presented by Moshe in the first person. This paves the way for the presentation of other messages through the auspices of the prophets.
What do we do without prophecy? Along the above lines, we can say that Torah Sheb’al Peh (the Oral Law) is a direct outgrowth of the phenomenon of Mishneh Torah. Fittingly, the basis of the Oral Law is called Mishnah. Devarim is to the first four books as the Six Books of Mishnah are to the whole of Torah Sheb’al Peh, all of which are Sinaitic. Moshe taught that an "eternal life he planted within us." We have the power to continue, create, and develop within Torah’s framework, each of us according to his abilities.
May we succeed in continuing Moshe’s legacy of planting fruit-bearing Torah in Jews’ hearts.