1 Chronicles 14:8-15

David Defeats the Philistines 8When the Philistines heard that David had been anointed king over all Israel, they went up in full force to search for him, but David heard about it and went out to meet them. 9Now the Philistines had come and raided the Valley of Rephaim;

10so David inquired of God: “Shall I go and attack the Philistines? Will you deliver them into my hands?” The LORD answered him, “Go, I will deliver them into your hands.” 11So David and his men went up to Baal Perazim, and there he defeated them. He said, “As waters break out, God has broken out against my enemies by my hand.” So that place was called Baal Perazim. Baal Perazim means the lord who breaks out.

12The Philistines had abandoned their gods there, and David gave orders to burn them in the fire. 13Once more the Philistines raided the valley; 14so David inquired of God again, and God answered him, “Do not go directly after them, but circle around them and attack them in front of the poplar trees. 15As soon as you hear the sound of marching in the tops of the poplar trees, move out to battle, because that will mean God has gone out in front of you to strike the Philistine army.”