2 Kings 3:20-22

20It happened in the morning 1about the time of offering the sacrifice, that behold, water came by the way 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 stood on the border. 22They rose early in the morning, and the sun shone on the water, and the Moabites saw the water opposite them as red as blood.