2 Samuel 5:22-24

22Once again the Philistines came up and spread out in the Valley of Rephaim. 23So David inquired of the LORD, who answered, “Do not march straight up, but circle around behind them and attack them in front of the balsam trees.1 24As soon as you hear the sound of marching in the tops of the balsam trees, move quickly, because this will mean that the LORD has gone out before you to strike the camp of the Philistines.”