1 Chronicles 20:1

20:1 It happened, at the time of the return of the year, at the time when kings go out [to battle], that Joab led forth the army, and wasted the country of the children of Ammon, and came and besieged Rabbah. But David stayed at Jerusalem. Joab struck Rabbah, and overthrew it.
-World English Bible

Other Translation

20:1 And it came to pass, that after the year was expired, at the time that kings go out [to battle], Joab led forth the power of the army, and wasted the country of the children of Ammon, and came and besieged Rabbah. But David tarried at Jerusalem. And Joab smote Rabbah, and destroyed it.
-King James Version