1 Chronicles 20-22:1 - David's sin and the ground for the temple

The start of chapter 20 deals with the time when David committed his infamous sin. Following this sin there are various victories.

Having ignored David's sin with Bathsheeba the writer does not ignore David's other major sin, namely taking a census of Israel. The account here includes some material that is not found in 2 Samuel. 

The text says that Satan incited David to take a census. David had all that he needed, for he had the Lord, and all his victories were given by the Lord. So he had no need to take the census and doing so betrayed a lack of trust. Joab seemed to recognise this. Note that although Satan incited David, David is still responsible. We may be tempted, but we have no need to give in to temptation, and if we do we can blame no one else but ourselves.

So David persisted with the census. After it was completed David seemed to realise that he had sinned. Quite possibly he realised it was wrong all along, but our depravity makes us carry on doing something even when we know it is wrong, then after the deed is done we "repent". Why do we behave like this? Two reasons. One the depravity of our soul, and secondly the deceitfulness of sin. Sin always fails to deliver what it promises.

Gad the seer gives David the three choices and David entrusts himself to the Lord. David accepted full responsibility for what he had done.

The latter part of chapter 21 (and 22:1) is concerned with David buying the ground that would become the site of the temple. Note that the temple is built on ground associated with repentance.