1 Chronicles 14:14-15

14David inquired again of God, and God said to him, “You shall not go up after them; circle around 1behind them and come at them in front of the baka-shrubs.

15When you hear the sound of marching in the tops of the baka-shrubs, then you shall go out to battle, for God will have gone out before you to strike the army of the Philistines.”