1 Chronicles 20:1-3

And it came to pass, at the time of the return of the year, at the time when kings go out to battle, that Joab led forth the army, and wasted the country of the children of Ammon, and came and besieged Rabbah. But David tarried at Jerusalem. And Joab smote Rabbah, and overthrew it. And David took the crown of their king from off his head, and found it to weigh a talent of gold, and there were precious stones in it; and it was set upon David’s head: and he brought forth the spoil of the city, exceeding much. And he brought forth the people that were therein, and cut them with saws, and with harrows of iron, and with axes. And thus did David unto all the cities of the children of Ammon. And David and all the people returned to Jerusalem.