2 Kings 3:20-22

20And it happened in the morning 1about the time of offering the sacrifice, that behold, water came from the direction of Edom, and the country was filled with water.

21Now all the Moabites heard that the kings had come up to fight against them. And all who were able to 2put on armor and older were summoned and they took their positions on the border. 22Then they got up early in the morning, and the sun shone on the water, and the Moabites saw the water opposite them as red as blood.