The most prominent part of this reading is the “inciting” of David by Satan. The notes from this same passage in 2 Samuel make it clear that there was nothing sinful about counting the army. However, there was no immediate threat, and so what is implied that is sinful, is an act of glorying and pride in the empire that had been accumulated and in the appearance that this is what David was putting his trust in–the number of warriors that he had. David should have known better. He knew that God had routed larger armies and that he had given victory to smaller ones. It was God’s favor that ensured victory and not the size of the army. Joab’s response to David’s requests reveals that Joab knew this was an act against God.
But once again, David shows why he is called “a man after God’s own heart.” For David’s sin, God gives him three choices of punishment: being swept away by his enemies, a plague, or a famine. David chooses the plague because to “fall into the hands” of the Lord is better than to fall into the hands of the enemy because David says, “the mercy of the Lord is very great.” And that merciful heart is revealed once again in very 15 of chapter 21. Even in the act of judging Israel for their sin, the Lord is “grieved” because of the calamity and brings and end to the judgment.
Matthew 10:28 records the words of Jesus who said the same. We should not fear what man can do to us. We need to fear God who has power not only over our bodies, but our souls. And what a blessed promise it is to know that God desires to be merciful. God wishes than none should perish, but all come to repentence (2 Pe. 3:9). It was true in David’s day and it is true today. It is better to fall into the hands of God than any other hands when we fall there in repentance acknowledging our sin and seeking help to follow what the Lord has commanded.