Judges 20:31-32

31The Benjaminites attacked the army, leaving the city unguarded. They began to strike down their enemy just as they had done before. On the main roads (one leads to Bethel, the other to Gibeah) and in the field, they struck down about thirty Israelites.

32Then the Benjaminites said, “They are defeated just as before.” But the Israelites said, “Let’s retreat and lure them away from the city into the main roads.”