2 Samuel 12:29-31
12:29 So David assembled all the army and went to Rabbah and fought against it and captured it.
12:30 He took the crown of their king from his head – it was gold, weighed about seventy-five pounds, and held a precious stone – and it was placed on David’s head. He also took from the city a great deal of plunder.
12:31 He removed the people who were in it and made them do hard labor with saws, iron picks, and iron axes, putting them to work at the brick kiln. This was his policy with all the Ammonite cities. Then David and all the army returned to Jerusalem.