The covenant Lord comes to establish a relationship. This relationship is not yet predicated upon the finished work of Christ at Calvary, so the judicial element demands law. Still, it also entails the fact that the God of the Law is the God also of grace. If He were not, there would be no hope of relationship and the covenantal purposes of God would be reduced to futility.
The laws found in Exodus through to Deuteronomy are given, for the most part, to restrain Israel’s sin and to proclaim an ethics of human value, regardless of social status, and of the unity of communal life. The commandments can be summed up in two: Deuteronomy 6:4-5 and Leviticus 19:6.
The 613 laws of the Torah can be boiled down to these two, but because these two are not realizable by corrupted humans, the other 611 spell out what this means in terms of living in a theocracy.
It must be recognized that it is a mistake to conflate the Pentateuch and the Law. The Law does not show up until we are sixty-nine chapters into the Pentateuch. Also, the role of faith is prominent in these books.
The Mosaic Covenant is Bilateral and Temporal
The covenant at Sinai was made with the children of Israel, who agreed to live as a Theocracy under God’s rule. The covenant relationship was predicated on holiness. While God’s holiness describes His Being and is absolute, fallen humanity does not possess the quality of holiness as a personal property. As beings we are sinful (Isa. 61:6; Eccles. 7:20; Psa. 51:5; Rom. 3:23). This means that any holiness we might “attain” is going to have to be God-approved. This is especially the case if God is going to dwell in our midst. In what is called “The Book of the Covenant” in Exodus 20-24 Israel discovers what external holiness looks like.
But what about God’s repeated command to, “be holy for I am holy” (Lev. 11:44-45; 19:2)? Doesn’t this indicate that there cannot be a disparity between God’s holiness and our external consecration? I don’t think so because as we do God’s will, even externally, we affirm His rectitude. We proclaim the rightness of His ways, and we learn from them. Israel could never change into “good people” internally without God performing the change – which is why the Mosaic covenant couldn’t work – but they could become different and separate through the Law. Thus, the great function of the Mosaic covenant, as well as showing Israel and all other people their insufficiency, was to separate the Jewish people enough to preserve them. And they had to be preserved; not because of the Mosaic covenant, but because of the Abrahamic covenant!
So when Moses finally confronts the nation with their responsibilities under the covenant they assent to enter into its fearful obligations.
And Moses took half the blood and put it in basins, and half the blood he sprinkled on the altar. Then he took the Book of the Covenant and read in the hearing of the people. And they said, “All that the LORD has said we will do, and be obedient. And Moses took the blood, sprinkled it on the people, and said, “This is the blood of the covenant which the LORD has made with you according to all these words.” – Exodus 24:6-8
As subsequent events would more than prove, the bilateral covenant was a failure in terms of creating a holy nation because of sinful human declension. But the covenantal nature of the Law and its particularity to this nation did something for Israel which guaranteed her eventual entering into the full fruition of God’s unconditional covenants. If it did nothing else, the Mosaic covenant ensured Israel’s survival as a people.
[T]he great struggle of biblical times was to preserve the identity of Israel in a world in which she was a small people (Deut. 7:7) and in an extremely vulnerable political situation, one in which autonomy was often de jure, but not de facto. Much of the biblical law…evidences a desire to establish a clear and durable border between the Israelites and the Canaanites among whom they lived (e.g., Lev 20:22-26).
Though the covenant law could only be temporal, it would serve a great purpose.
 These points are made by G. I. Davies, “Introduction to the Pentateuch”, in The Oxford Bible Commentary: The Pentateuch, edited by John Barton and John Muddiman, 41
 See Mark 12:28-31.
 As seen, e.g., from Genesis 15:6; 22:5-12; Exod. 19:9; Num. 14:11. Cf. Hebrews 11.
 In saying this I am not claiming that holiness is not an essential ingredient in God’s activity (Exod. 15:5; Psa. 65:5). But contrary to men like John Webster, Holiness, 39-41, I would stop short of equating God’s holiness solely in terms of God’s activity. I also reject the idea of holiness as “wholly other” (as e.g. in Bernhard Anderson, Contours of Old Testament Theology, 46-47). To be communicable in any sense, the “powers” or attributes of God must be comprehensible, though never exhaustively so.
 Cf. Exodus 24:7
 Not to mention the covenants with Phinehas and David which we will examine.
 I hesitate to use the word “natural” because originally human beings were not constituted sinners.
 This was clearly understood early on. For example, Joshua tells the elders of Israel, “You cannot serve the LORD, for He is a holy God. He is a jealous God; He will not forgive your transgressions nor your sins.” – Joshua 24:19
 Jon D. Levenson, Sinai & Zion, 120
 If one understands “fulfillment” in terms of consummation then all should agree with this statement: “The Mosaic, or Sinaitic, covenant that dominated Israel’s life in the Old Testament is superseded by the new covenant and therefore has no ongoing ramification for the fulfillment of God’s purposes (cf. Jer. 31:31-32; Heb. 8:6-13, esp. v.13).” – Robert L. Saucy, The Case for Progressive Dispensationalism, 40 n.1. Cf. 59 n.1