Before his passing, Moshe began to prepare Bnei Yisrael for their entry into the Land of Israel by recounting all that they had experienced during their 40 years in the desert. The Torah adds that, as part of this address, Moshe “explained this teaching.” Rashi interprets this to mean that he taught Bnei Yisrael the Torah in 70 languages.
Why did Moshe translate the Torah at this point? Bnei Yisrael were about to begin their conquest of the land of Canaan, a process that would involve seven years of battle and another seven years dedicated to dividing and settling the land. Why did Moshe find it necessary to translate the Torah specifically now, as Bnei Yisrael prepared to enter this phase?
By translating the Torah, Moshe was carrying out a crucial component of Bnei Yisrael’s conquest of the seven nations who occupied the Land of Israel. For everything in the physical world has a spiritual source, and any change that takes place on the physical plane must first be executed in a spiritual sense. According to Kabbalah, the seven nations who occupied the land of Canaan represented the 70 original nations of humanity and contained their spiritual source. Moshe’s translation of the Torah, which breached the language barrier between the Torah and the 70 nations, constituted a spiritual victory for the Torah over any opposition it faced from the other nations of the world. Only once Moshe had achieved a spiritual victory over the nations could Bnei Yisrael succeed in defeating them physically.
—Sichos Kodesh 5730, vol. 1, pp. 358–359
