Charles Spurgeon Commentary 1 Chronicles 21:7-15

"And God was displeased with this thing; therefore he smote Israel. And David said unto God, I have sinned greatly, in that I have done this thing: but now, put away, I beseech thee, the iniquity of thy servant; for I have done very foolishly. And Jehovah spake unto Gad, David`s seer, saying, Go and speak unto David, saying, Thus saith Jehovah, I offer thee three things: choose thee one of them, that I may do it unto thee. So Gad came to David, and said unto him, Thus saith Jehovah, Take which thou wilt: either three years of famine; or three months to be consumed before thy foes, while the sword of thine enemies overtaketh thee; or else three days the sword of Jehovah, even pestilence in the land, and the angel of Jehovah destroying throughout all the borders of Israel. Now therefore consider what answer I shall return to him that sent me. And David said unto Gad, I am in a great strait: let me fall, I pray, into the hand of Jehovah; for very great are his mercies: and let me not fall into the hand of man. So Jehovah sent a pestilence upon Israel; and there fell of Israel seventy thousand men. And God sent an angel unto Jerusalem to destroy it: and as he was about to destroy, Jehovah beheld, and he repented him of the evil, and said to the destroying angel, It is enough; now stay thy hand. And the angel of Jehovah was standing by the threshing-floor of Ornan the Jebusite." — 1 Chronicles 21:7-15 (ASV)

Therefore he smote Israel. And David said unto God, I have sinned greatly, because I have done this thing: but now, I beseech thee, do away the iniquity of thy servant; for I have done very foolishly. And the LORD spake unto Gad, David's seer, saying, GO and tell David, saying, Thus saith the LORD, I offer thee three things: choose thee one of them, that I may do it unto thee. So Gad came to David, and said unto him, Thus saith the LORD, Choose thee either three years' famine; or three months to be destroyed before thy foes, while that the sword of thine enemies overtaketh thee; or else three days the sword of the LORD, even the pestilence, in the land, and the angel of the LORD destroying throughout all the coasts of Israel. Now therefore advise thyself what word I shall bring again to him that sent me. And David said unto Gad, I am in a great strait: let me fall now into the hand of the LORD; for very great are his mercies: but let me not fall into the hand of man. So the LORD sent pestilence upon Israel and there fell of Israel seventy thousand men. And God sent an angel unto Jerusalem to destroy it: and as he was destroying, the LORD beheld, and he repented him of the evil, and said to the angel that destroyed, It is enough, stay now thine hand.

See the power of the mercy of God; even when the angel has drawn his sword, and is already executing the Lord's just judgments, God's mercy interposes, and holds back the blade of death. Should we not love the Lord for his great longsuffering toward us? He hath not dealt with us after our sins; nor rewarded us according to our iniquities.