Thematic Bible: Ammonites defeated and tortured

So Joab fought against Rabbah of the Ammonites and captured the royal city. Joab then sent messengers to David, saying, "I have fought against Rabbah and have captured the water supply of the city. So now assemble the rest of the army and besiege the city and capture it. Otherwise I will capture the city and it will be named for me." read more.
So David assembled all the army and went to Rabbah and fought against it and captured it. 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. 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.