'Behind' in the Bible

When Joab observed that the battle lines were set up to oppose him both in front and behind, he appointed some special forces from Israel and arrayed them to oppose the Arameans,

Later the next spring, at the time that kings go out to fight, Joab led out the army, ravaged the territory of the Ammonites, and then went out and attacked Rabbah, while David remained behind in Jerusalem. Joab besieged Rabbah and conquered it.