1 Chronicles 21:16-19

16Then 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.

17And 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.”

18Therefore, 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.

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