Moshe in the Torah, Yishayahu in the Prophets, and Yirmiyahu in the Writings, all express their amazement at the situation and fate of the nation of Israel using the same expression - "eikha".
Moshe saw what Yishayahu and Yirmiyahu did not see: that the source of the "eikha" is also the source of the growth of the Oral Law. That is why Moshe's question, "How shall I bear alone your troubles," is lodged in the midst of chapters that deal entirely with the command about the inheritance of the land, and its fulfillment. There is no better expression of the Oral Law than the inheritance of Eretz Yisrael: "And the manna ceased the next day, when they ate of the produce of the land." Eretz Yisrael is not a land of heavenly manna, but rather a land of wells that are dug in the depths of the earth. It is the land of Avraham, Yitzchak and Yaakov, to whom God's Name was not known until they discovered it through their personal trials and tribulat. It is the land of the forefathers, who fulfilled all of the mitzvot out of their own consciousness, although they had not stood at Mt. Sinai and had never received the heavenly Torah. And so Rav Kook zt"l writes, concerning Eretz Yisrael, in his Orot Ha-Torah (1:3): "When Eretz Yisrael is built up, and all her children live upon her… then the ORAL LAW comes alive in all her glorious splendour…."
In parashat Devarim, even before Moshe's glory fades, it radiates anew: "These are the words that Moshe spoke." The first threads that will join Moshe and Bnei Yisrael anew into a single entity are woven here. The first cords that will once again bind the Torah of Moshe - the Written Law - to the Torah of speech - the Oral Law, start to be interlaced. All this is achieved from Moshe's side. As for Bnei Yisrael, we learn in the Midrash (ibid.): "The Holy One said to Moshe: Since they accepted upon themselves your admonishment, you must bless them." After forty years, Bnei Yisrael begin to take their teacher's words to heart, and they return to him.
Excerpted from the article "The Oral Law and the Secret of 'Eikha'" by Rabbi Yaakov Medan. Click here to read the full article.