1 Chronicles 20:2

At the time of the return of the year, at the time when kings go out, Joab led out 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.

He brought out the people who were in it, and had them cut with saws, with iron picks, and with axes. David did so to all the cities of the children of Ammon. Then David and all the people returned to Jerusalem.

After this, war arose at Gezer with the Philistines. Then Sibbecai the Hushathite killed Sippai, of the sons of the giant; and they were subdued.

Again there was war with the Philistines; and Elhanan the son of Jair killed Lahmi the brother of Goliath the Gittite, the staff of whose spear was like a weaver’s beam.