2 Samuel ends with the same unsettled kind of feeling that much of the book gave to us. The first troubling thing we read is in verse 1, “Again the anger of the Lord was kindled against Israel, and he incited David against them…” The whole census idea was God’s idea to give Him reason to punish the Israelites! The reason for the anger is not stated; most likely it is the usual reason, their rebellion against God and their worship of false gods.
In the end, we see God’s mercy; he calls off the angel of the LORD as it is reaching out to strike Jerusalem with destruction. In response, David purchases the threshing floor where he saw the angel, builds an altar, and offers a sacrifice to the LORD to avert the disaster.
2 Samuel actually ends on a positive note, the LORD’s mercy shown to David. It also ends with a bit of foreshadowing. The threshing floor purchased by David would be the site of Solomon’s temple (and the later temple at the time of Jesus, and the current temple mount). It’s very location would be an ever-present sign of God’s mercy.