Matthew Henry Commentary 2 Samuel 24:1-9

"And again the anger of Jehovah was kindled against Israel, and he moved David against them, saying, Go, number Israel and Judah. And the king said to Joab the captain of the host, who was with him, Go now to and fro through all the tribes of Israel, from Dan even to Beer-sheba, and number ye the people, that I may know the sum of the people. And Joab said unto the king, Now Jehovah thy God add unto the people, how many soever they may be, a hundredfold; and may the eyes of my lord the king see it: but why doth my lord the king delight in this thing? Notwithstanding, the king`s word prevailed against Joab, and against the captains of the host. And Joab and the captains of the host went out from the presence of the king, to number the people of Israel. And they passed over the Jordan, and encamped in Aroer, on the right side of the city that is in the middle of the valley of Gad, and unto Jazer: then they came to Gilead, and to the land of Tahtim-hodshi; and they came to Dan-jaan, and round about to Sidon, and came to the stronghold of Tyre, and to all the cities of the Hivites, and of the Canaanites; and they went out to the south of Judah, at Beer-sheba. So when they had gone to and from through all the land, they came to Jerusalem at the end of nine months and twenty days. And Joab gave up the sum of the numbering of the people unto the king: and there were in Israel eight hundred thousand valiant men that drew the sword; and the men of Judah were five hundred thousand men." — 2 Samuel 24:1-9 (ASV)

Because of the people's sin, David was allowed to act wrongly, and in his chastisement, they received punishment. This example sheds light on God's government of the world and provides a useful lesson.

The pride of David's heart was his sin in numbering the people. He thought by this action to appear more formidable, trusting in an arm of flesh more than he should have, even though he had written so much about trusting in God alone. God does not judge sin as we do. What appears to us as harmless, or at least merely a small offense, may be a great sin in God's sight, who discerns the thoughts and intents of the heart.

Even ungodly people can discern evil tempers and wrong conduct in believers, of which believers themselves often remain unaware. But God seldom allows those whom He loves the pleasures they sinfully covet.