Read 1 Chronicles 20:3 Using Other Translations
And he brought out the people that were in it, and cut them with saws, and with harrows of iron, and with axes. Even so dealt David with all the cities of the children of Ammon. And David and all the people returned to Jerusalem.
And he brought out the people who were in it and set them to laborwith saws and iron picks and axes. And thus David did to all the cities of the Ammonites. Then David and all the people returned to Jerusalem.
He also made slaves of the people of Rabbah and forced them to labor with saws, iron picks, and iron axes. That is how David dealt with the people of all the Ammonite towns. Then David and all the army returned to Jerusalem.