So Gad came to David, and said to him, Thus says Yahweh, Take which you will:
Chapters 17-21 give the writer’s first account of what God promised David in the Davidic Covenant. The things that God promised, He provided in David’s lifetime and shortly after that. They included victory in battle, expanded influence, and a glorious reputation. The record of this promise is in 1 Chronicles 17:8, and the fulfillment is in chapters 18-20. The second promise was a secure, peaceful place for Israel that made necessary a place for Yahweh to dwell among His people in fellowship. The record of this promise is in 1 Chronicles 17:9-12, and chapter 21 guarantees its fulfillment. These promises and their fulfillments would have given the original readers of Chronicles great confidence. They would have encouraged them that Yahweh would yet fulfill those promises in the Davidic Covenant that had not yet materialized but were still future for them. The record should have the same effect on us today.