Moses’ covenant prepares the way for Israel to have kings (Deuteronomy 17:14- 20). The king after God’s own heart is David, and with him God makes a covenant about future kings.
Thus says the LORD of hosts [to David]… “When your days are fulfilled and you lie down with your fathers, I will raise up your offspring after you, who shall come from your body, and I will establish his kingdom. He shall build a house for My name, and I will establish the throne of his kingdom forever…. And your house and your kingdom shall be made sure forever before Me. Your throne shall be established forever.” (2 Samuel 7:8, 12-13, 16)
Now these are the last words of David: The oracle of David, the son of Jesse, the oracle of the man who was raised on high, the anointed of the God of Jacob, the sweet psalmist of Israel…. “For does not my house stand so with God? For He has made with me an everlasting covenant, ordered in all things and secure” (2 Samuel 23:1, 5 cf. Psalm 89:20-37)
This covenant is conditional for the individual descendants of David. If a king of David’s line honors God, then God will honor and prosper that man’s kingship (Psalm 132:11-12; cf. Deuteronomy 17:14-20). If a Davidic king rejects God, God will punish or reject that individual (2 Samuel 7:14; 1 Chronicles 28:9). Through the years, David’s descendants prove a mixture of good and bad. Eventually they become so wicked that God permanently removes the line of kings from David’s earthly throne (Jeremiah 22:30; 36:30). But that does not affect the King to whom the covenant ultimately points. For He will reign from heaven, enthroned with God Himself (Acts 2:30-36; Ephesians 1:20-21; Revelation 3:21).