1 Chronicles 20:2-3

2David took the crown from the head of their king—its weight was found to be a talent of gold, and it was set with precious stones—and it was placed on David’s head. He took a great quantity of plunder from the city

3and brought out the people who were there, consigning them to labor with saws and with iron picks and axes. David did this to all the Ammonite towns. Then David and his entire army returned to Jerusalem.