Haazinu Dvar Torah
Parshas Haazinu is a poetic speech that Moshe gives to the Jewish nation right before his death. The Parsha opens with Moshe telling the heavens and the earth to listen to his parting words. The simple question is, how could Moshe ask something inanimate to hear his words?
Rashi on this verse tells us that this statement was more poetic, and not meant to be taken literally. Moshe was telling the Jews once he is gone, they shouldn't feel that they can stray from the path of Torah, because the heaven and earth—which are immortal—will eternally respond to the Jews’ behaviors. If the Jews follow God commandments, they will have physical sustenance from the heavens, such as rain, and from the earth, such as produce. If they do not follow God's commandments, however, they will be lacking in sustenance (as stated in Shema, Devarim 11:17).
We can see from this that Moshe's objective was that the Jews follow Torah, even after he is gone. Moshe understood man's primary concern is survival. This is why he used the heaven and the earth as motivation for the Jews to follow Torah.
Another question arises, is physical sustenance the only objective of man? Of course the answer is no, but the truth is that most people are not on the highest level of perfection. Yet, Moshe must appeal to their physical survival. But the ultimate objective is that man realizes God’s will, and that man enjoys God’s wisdom. God desires that man has the highest level of enjoyment in his existence. And what is that enjoyment? The Rambam says it is the wisdom of Torah, and all the mitzvos target this objective with their halachic formulations, as seen in the Gemara.
In summation, to arrive at the objective of enjoying life through wisdom, one must first be compelled to follow Torah out of his physical needs…and through following Torah, man will ultimately see God’s wisdom.