Joshua 10:17

‘ And it was told Joshua saying, “The five kings are found hidden in the cave at Makkedah.”

Capturing the kings would be looked on by the captors as a real coup. They may even have felt that now the pursuit could be relaxed while they concentrated on entering the caves, dealing with any guards, and apprehending the kings. Messengers were immediately sent to Joshua. But Joshua was a wise general and knew that what was most important was to reduce as much as possible the manpower of the Canaanite cities which had taken part in the attack.