The three kings were in a desperate situation as their armies and animals had no water after a seven day march. Elisha told them to dig ditches in the valley, though there was no wind or rain. By digging ditches and having faith in God's word, water came from Edom and filled the valley, saving the armies from dying of thirst. Their act of faith in digging the ditches despite the improbability of water, showed their trust that God would provide as He said.