Judges 20:31-33

31The Benjamites came out to meet them and were drawn away from the city. They began to inflict casualties on the Israelites as before, so that about thirty men fell in the open field and on the roads—the one leading to Bethel and the other to Gibeah. 32While the Benjamites were saying, “We are defeating them as before,” the Israelites were saying, “Let’s retreat and draw them away from the city to the roads.” 33All the men of Israel moved from their places and took up positions at Baal Tamar, and the Israelite ambush charged out of its place on the west of Gibeah.