“But Sihon, the king of Heshbon, would not let us pass through his country. The Lord your God had made him very stubborn. The Lord did this so he could let you defeat King Sihon. And today, we know that really happened!
The Lord wanted those people to think they were strong. Then they would fight against Israel. This way he could destroy them without mercy. He could destroy them the way the Lord had commanded Moses to do.
The army of Benjamin came out of the city of Gibeah to fight the army of Israel. The army of Israel backed up and let the army of Benjamin chase them. In this way, the army of Benjamin was tricked into leaving the city far behind them.