Deuteronomy 30 - As you read carefully you should note that God predicts Israel's failure and eventual deportation to the nations of the world. But, God makes a serious promise in saying that He will bring them back to their land and they will possess it fully, a promise that is yet to be fully fulfilled. This is known as the Palestinian Covenant. There is a also a serious call to Israel to renew their love for the Lord and a desire to obey Him fully.
Deuteronomy 31 - This chapter begins Moses' last words to the people of Israel and to Joshua as well. He warns Israel of God's judgment if they turn from Him. Moses also encourages Joshua with the responsibility of bringing the children of Israel into the Promised Land. At the end of this chapter Moses speaks of a song he has written for Israel to sing. This song comes in the next chapter.