2 Samuel 24:8-10

American Standard Version

⁸ So when they had gone to and fro through all the land, they came to Jerusalem at the end of nine months and twenty days. ⁹ 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.

¹⁰ And David’s heart smote him after that he had numbered the people. And David said unto Jehovah, I have sinned greatly in that which I have done: but now, O Jehovah, put away, I beseech thee, the iniquity of thy servant; for I have done very foolishly.