1 Chronicles 21:14-23 (NKJV)

¹⁴ So the Lord sent a plague upon Israel, and seventy thousand men of Israel fell. ¹⁵ And God sent an angel to Jerusalem to destroy it.

As he was destroying, the Lord looked and relented of the disaster, and said to the angel who was destroying, “It is enough; now restrain your hand.” And the angel of the Lordstood by the threshing floor of Ornan the Jebusite.

¹⁶ Then David lifted his eyes and saw the angel of the Lord standing between earth and heaven, having in his hand a drawn sword stretched out over Jerusalem.

So David and the elders, clothed in sackcloth, fell on their faces. 

¹⁷ And David said to God, “Was it not I who commanded the people to be numbered?

I am the one who has sinned and done evil indeed; but these sheep, what have they done? Let Your hand, I pray, O Lord my God, be against me and my father’s house, but not against Your people that they should be plagued.”

A mitzvah of giving a sacrifice or offering turns a way God’s wrath:

¹⁸ Therefore, the angel of the Lord commanded Gad to say to David that David should go and erect an altar to the Lord on the threshing floor of Ornan the Jebusite. 

¹⁹ So David went up at the word of Gad, which he had spoken in the name of the Lord. 

²⁰ Now Ornan turned and saw the angel; and his four sons who were with him hid themselves, but Ornan continued threshing wheat. 

²¹ So David came to Ornan, and Ornan looked and saw David.

And he went out from the threshing floor, and bowed before David with his face to the ground. 

²² Then David said to Ornan, “Grant me the place of this threshing floor, that I may build an altar on it to the Lord. You shall grant it to me at the full price, that the plague may be withdrawn from the people.”

²³ But Ornan said to David, “Take it to yourself, and let my lord the king do what is good in his eyes. Look, I also give you the oxen for burnt offerings, the threshing implements for wood, and the wheat for the grain offering; I give it all.”