Establishing the Mosaic covenant marked a critical point in the history of redemption and the unfolding of the covenant of grace. Having been redeemed from slavery by grace, the people of Israel were constituted as a nation and received laws to identify them as the Lord’s holy people so that they might bear witness to the one, true creator God among the Gentile nations (Ex. 19:5).
Although the Mosaic covenant is key to redemptive history, it was not the final covenant to unfold the covenant of grace. Instead, the Mosaic covenant pointed beyond itself to a day when the Law would be written on the hearts of God’s people and not just on tablets of stone (Deut. 10:12–22).
In addition to looking for the Law to be written on the heart, the Mosaic law also gave the people of Israel hope for a righteous ruler. Deuteronomy 17:14–20 looks to the days when an Israelite king will sit over the nation and rule with justice and righteousness according to the Law. Under the Davidic covenant, the next “sub-covenant” in the covenant of grace, this hope begins to find fulfillment as God chooses the family from which this holy king will come.
The Davidic covenant was established after David brought the ark of the covenant to Jerusalem. At that point, David expressed his desire to build a house for God, but God replied that He would be the one to build a house for David (2 Sam. 7:1–17). The prophet Nathan was His mouthpiece through which the Creator delivered His great promises to David and the Israelite nation.
These promises come in the context of a covenant with David, the greatest king of the old covenant. As we would expect, the covenant is based on the Lord’s sovereign grace. First, God chooses David without making any reference to the monarch’s achievements; rather, He is king simply because God has willed it (v. 8). Second, David is told that Israel will have peace under his reign and the reigns of his descendants, who will likewise be established as rulers over Israel (vv. 9–13). Finally, David and his sons will enjoy having God as their Father. They will receive His discipline, but the Lord’s love and mercy will never depart from David’s line, ensuring that there will always be a Davidite on the throne in the kingdom of heaven (vv. 14–16).