1 Chronicles 14:14-15

14So David again asked God what he should do. This time God told him, ‘Do not march straight towards them. Instead, go round behind them. Then attack them from the other side, where the poplar trees are.

15When you hear a noise in the tops of the trees like marching men, go out to attack them. Then you will know that God has gone in front of you. He will knock down the Philistine army for you.’