Moses said to the people:
"Now, Israel, hear the statutes and decrees which I am teaching you to observe,
that you may live, and may enter in and take possession of the land
which the LORD, the God of your fathers, is giving you."
I like the ambiguity of the highlighted phrase. It makes the attentive listener say, "Wait, is Moses teaching Israel how to observe the statutes and decrees, or is he teaching them the statutes and decrees in order for Israel to observe them?"
And of course it's the latter. In teaching Israel the LORD's statues and decrees, Moses places life and death before them in order for them to choose life.
Moses does not teach Israel for his health. He does not give them the LORD's statutes and decrees indifferently, for their situational awareness. He does it because he loves the LORD's people, with a love analogous (in the weak way human love can be) to the LORD's own infinite love for His people.
For their part, Israel -- collectively and individually -- have a real choice to make. Listening to Moses isn't enough for them to live. Learning, even studying, the LORD's statutes and decrees isn't enough for them to live. They need to observe the Law, to follow the teaching, to conform themselves to the LORD's will. To enable them to do that is why the LORD sent Moses to them.