Parashat Devarim (Deut.1:1-3:22) begins the final words of Moses to the nation of Israel, prior to his death. Just five verses into the book of Devarim, Moses demonstrates how the Torah is to be transmitted as we read, “Moses began to explain this Torah.”
Note, that the verse does not say that Moses simply read the Torah to Israel—he explained the meaning of those words. This is a vital dimension of the Oral Torah, it preserves the original intent and meaning of God's instructions. Abarbanel, the great Spanish sage taught that Moses’ harnessed the power of the Oral Torah, as spoken by the Creator on Mount Sinai. The Oral Torah is central to Jewish observance, without it Israel cannot lay tefillin, kosher meat, get married or properly conduct themselves on Shabbat.
Moses' final discourse is unique because he addresses Israel in his own words.
He speaks to the nation for 37 days and does so in the first person. He speaks from the heart. The gematria of ha-lev (the heart) = 37.
The book of Devarim is likened to the second set of tablets, hewn by Moses' own hand but inscribed with God’s words—symbolic of HaShem’s method for transmitting and preserving the Torah—via His teachers. This confirms Israel as Nation chosen by God to transmit Torah wisdom. The Jewish People understand the necessity of teaching both Written and Oral Torah.
Moses reproves Israel for their missteps which lengthened their journey to the Promised Land, a prophetic lesson that the final Redemption depends on Israel's desire to possess the land and fully embrace their mission. More importantly, we are all beneficiaries of the fact that the nation of Israel is our teacher. As Isaiah taught, "And many peoples shall go forth and say: 'Come and let us go up to the mountain of the Lord, to the House of the God of Jacob; And He will teach us His ways, And we will walk in His paths.' For out of Zion shall go forth the Law, and the word of the Lord from Jerusalem.