2 Samuel 5:22-24

The Philistines came up once again and spread out in the Valley of Rephaim. When David inquired of the LORD, He said, “You shall not go up, but circle around behind them and come at them in front of the balsam trees. And when you hear the sound of marching in the tops of the balsam trees, then you shall pay attention and act promptly, for at that time the LORD will have gone out before you to strike the army of the Philistines.”