1 Chronicles 20:1-4

Then it happened in the spring, at the time when kings go out to battle, that Joab led out the army and ravaged the land of the sons of Ammon, and came and besieged Rabbah. But David stayed in Jerusalem. And Joab struck Rabbah and overthrew it.

David took the crown of their king from his head, and he found it to weigh a talent of gold, and there was a precious stone in it; and it was placed on David’s head. And he brought out the spoils of the city, a very great amount.

He brought out the people who were in it, and put them to work at saws, iron picks, and axes. And David did the same to all the cities of the sons of Ammon. Then David and all the people returned to Jerusalem.

Now it came about after this, that war broke out at Gezer with the Philistines; then Sibbecai the Hushathite killed Sippai, one of the descendants of the giants, and they were subdued.