The Mosaic Covenant as a Historical Placeholder for Other Covenants
If the commandments in the ‘Ten Words’ on Sinai (Exod. 20) and all those that followed in their train were too stringent for a fallen people to keep, at least the covenant God made with Israel, and which they voluntarily entered into (in Exod. 24), distinguished them among the other nations of the world. It did this to the extent that they were preserved as a distinct people in continuity with Abraham, Isaac and Jacob.
Just as the Noahic covenant guarantees the perpetuation of the regulation and predictability of the rhythms of nature,thereby creating the stage of history for God’s program to play out upon, the Mosaic covenant acts to set the covenants with David and Phinehas within a theocratic outlook – even if both of these covenants transcend the temporary “old covenant” and are embraced by the coming New covenant. Another way to say this is to imagine the people of Israel as connecting the Mosaic covenant to the New covenant brought upon Israel at Christ’s return (Isa. 61:2b-3; Jer. 31:31-37); a covenant that supersedes the old one, but without morphing the promises God made out of all recognition.
That preservation through the Law, even when it was being reduced to formal hypocrisy – as it was much of the time (e.g. Isa. 1:2-23; Mal. 2:10-11) – was enough to keep Israel from being absorbed into the peoples and cultures surrounding them. The elaborate details of the Tabernacle, with its importance for ethnic and religious identity, and the whole Levitical system, served to isolate the Jews enough to keep them separate, therefore guaranteeing their continuance. Looked at this way the covenant with Israel in Exodus and Deuteronomy served as a place-holder for the covenants to follow; the ‘Priestly’, the Davidic and the New. Israel needed to remain a static entity so that the covenants so bound up with the nation could be fulfilled. Not only that, but because the interests of the nation were indelibly intertwined with the Abrahamic covenant, that covenant too was secured within the continuing people called the Jews.
Future Blessing and a Palestinian Covenant?
The Book of Deuteronomy finds Israel on the verge of entering the land which God has promised them. Up until this point the people have not distinguished themselves for their faith in God. But the Lord is not going to remove the faith requirement out of the way. What was true for the writer of Hebrews is true for Israel east of Jordan, “without faith it is impossible to please Him.” (Heb.11:6). So Israel will have to face its foes; some of them (i.e. the city of Jericho – cf. Josh. 3:16; more sons of Anak – Josh. 15:13-14), look formidable. But YHWH has promised to go before them (Deut. 1:30, 42; 20:4). Moses reminds the people about the incident which cost the lives of twenty-four thousand people at Baal-Peor (Num. 25), and the giving of the Ten Commandments at Sinai (see Deut. 4:3-13). Then he turns to their fortunes if they decline from the Law. God will cast them out of the land and scatter them abroad (Deut.4:26-27), but He will also do something about their plight “in the latter days” (Deut. 4:30). The reason for this mercy is “He will not forsake you nor destroy you, nor forget the covenant of your fathers which He swore to them.” (Deut.4:31). The “covenant of your fathers” is clearly not the Mosaic covenant which He is recalling to them. God’s dealing with Israel is covenantally determined, but as we have seen, it is determined principally on account of the Abrahamic covenant, together with the ‘Priestly’ covenant (see below) and the covenant He will make with David.
The hope partially expressed in chapter 4 of Deuteronomy is broadened somewhat in chapter 30. Building on the blessings and cursings connected with the Mosaic covenant in chapter 28, there is a promise of restoration, even salvation, especially in the first nine verses.
Now it shall come to pass, when all these things come upon you, the blessing and the curse which I have set before you, and you call them to mind among all the nations where the LORD your God drives you, and you return to the LORD your God and obey His voice, according to all that I command you today, you and your children, with all your heart and with all your soul, that the LORD your God will bring you back from captivity, and have compassion on you, and gather you again from all the nations where the LORD your God has scattered you. If any of you are driven out to the farthest parts under heaven, from there the LORD your God will gather you, and from there He will bring you. Then the LORD your God will bring you to the land which your fathers possessed, and you shall possess it. He will prosper you and multiply you more than your fathers. And the LORD your God will circumcise your heart and the heart of your descendants, to love the LORD your God with all your heart and with all your soul, that you may live. Also the LORD your God will put all these curses on your enemies and on those who hate you, who persecuted you. Also the LORD your God will put all these curses on your enemies and on those who hate you, who persecuted you. The LORD your God will make you abound in all the work of your hand, in the fruit of your body, in the increase of your livestock, and in the produce of your land for good. For the LORD will again rejoice over you for good as He rejoiced over your fathers… – Deuteronomy 30:1-9
After the dispersion of Israel at an undefined future date, they will be brought back to their own land. The crucial thing to notice in this passage is the language of regeneration. It is God Himself who will cause His people “to love the LORD your God with all your heart and with all your soul.” There is also a promise of prosperity to go along with the change of heart. It will take the passage of time until the Prophets pick up on these things and set them within another covenant – a covenant to transcend the old covenant at Sinai.
 If this were not true in OT times the lineage of Jesus from Abraham and David in Matthew 1 (cf. Rom. 1:4) could never have been established.
 Notice how God calls the creation to witness against His people (‘heaven and earth’ is a merism – a phrase which describes a totality through the use of opposites). Israel is central to the Creation Project and ought to see itself as an instrument for good in God’s hand in the restoration of the world after the Fall.
 I am aware that verse 10 places a condition, “if you obey…”, but obedience is promised through the internalizing work of God in the hearts of His people.