1 Chronicles 20:1-2

1At the turn of the year, the season when kings go out to war, Joab led out the army and devastated the land of the Ammonites. He went and besieged Rabbah, while David remained in Jerusalem. Joab smote Rabbah and left it in ruins.

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 vast amount of spoils from the city.