Moses said to the people:In giving Israel his law, God offers his own people the roadmap for obedience and, in particular, the obedience that leads to life (Deut 4:2, Lev 18:5). Moreover, in obeying God, Israel’s virtue serves to demonstrate to the entire world that Israel’s God is the true God, for no other nation has gods so close to it as the LORD.
“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.
In your observance of the commandments of the LORD, your God,
which I enjoin upon you,
you shall not add to what I command you nor subtract from it.
Observe them carefully,
for thus will you give evidence
of your wisdom and intelligence to the nations,
who will hear of all these statutes and say,
‘This great nation is truly a wise and intelligent people.’
For what great nation is there
that has gods so close to it as the LORD, our God, is to us
whenever we call upon him?
Or what great nation has statutes and decrees
that are as just as this whole law
which I am setting before you today?"
However, mere external obedience to the law is not sufficient, for Moses states that Israel is to love God with all their heart (Deut 6:4-8) and Moses vividly elaborates on this mandate by calling on Israel to circumcise their hearts in order to love and obey God (Deut 10:10-16). To do so, is life; failure to do so leads to exile.
In Deut 30:1-6, it is clear that the curse of exile is inevitable, and it seems right to infer that this is due to Israel’s inability to circumcise their collective hearts. Instead, upon return from exile it is God who will circumcise Israel’s heart so that they would be enabled to obey him.