Albert Barnes Commentary Judges 15:9

"Then the Philistines went up, and encamped in Judah, and spread themselves in Lehi." — Judges 15:9 (ASV)

Spread themselves - An expression used of the Philistine mode of war (2 Samuel 5:18; 2 Samuel 5:22), alluding to the compact way in which they came up the wadis, and then dispersed. Lehi is so called by anticipation .