2 Samuel 10:3

10:3 the Ammonite officials said to their lord Hanun, “Do you really think David is trying to honor your father by sending these messengers to express his sympathy? No, David has sent his servants to you to get information about the city and spy on it so they can overthrow it!”

2 Samuel 12:31

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.