We must not lose sight of the context. Here the context is the whole of chapter 30, which falls naturally into three interconnected parts:
Verses 1-10 are all about the Hebrew root shub ("return," "repent," "restore," "again"). In fact these verses are artfully arranged in a concentric structure based upon seven occurrences of this theologically significant concept, as well as an alternating pattern of the "returns" of both Israel ("you" in Moses' address to the people) and God:
A If you call (hashevota) them to mind…,
and return (shavta) to the LORD your God (vv. 1-2)
B Then the LORD…will restore (shav shevutka) your fortunes,
gathering you again (shav) from all the peoples (v. 3-7)
X You shall again (tashuv) obey the LORD (v. 8)
B′ The LORD will again (yashuv) take delight in prospering you (v. 9)
A′ Because you turn (tashuv) to the LORD your God with all your heart and with all your soul (v. 10)
This wonderful intermezzo on the importance of repentance is deepened by the metaphor of return. Repentance means a radical change in direction, a turning away from one allegiance in order to embrace another. As a result of Israel's "return" to God (vv. 1-2), God will "return" Israel to the land of promise (v. 3), even from the "ends of the world" (v. 4), where Israel will prosper (vv. 5-7).
Can they do it? "Of course," Moses says in verses 11-14. The torah (God's instruction, guidance, and revelation) may have originated in heaven, but Moses and the prophets have made it available for all (vv. 12-13). In fact, it is "very near" (v. 14). Israel will hear it read and preached upon at all their festivals.
St. Paul cites this passage in Romans 10:4-10. What Moses says about the torah, however, is what Paul says about Christ. If the torah is the supreme example of God's intention for the world in Deuteronomy, Christ now assumes that responsibility for the Christian.
9and the Lord your God will make you abundantly prosperous in all your undertakings, in the fruit of your body, in the fruit of your livestock, and in the fruit of your soil. For the Lord will again take delight in prospering you, just as he delighted in prospering your ancestors, 10when you obey the Lord your God by observing his commandments and decrees that are written in this book of the law, because you turn to the Lord your God with all your heart and with all your soul.
11 Surely, this commandment that I am commanding you today is not too hard for you, nor is it too far away. 12It is not in heaven, that you should say, Who will go up to heaven for us, and get it for us so that we may hear it and observe it? 13Neither is it beyond the sea, that you should say, Who will cross to the other side of the sea for us, and get it for us so that we may hear it and observe it? 14No, the word is very near to you; it is in your mouth and in your heart for you to observe.
New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org