2 Kings 3:20-24

It happened in the morning about the time of offering the sacrifice, that behold, water came by the way of Edom, and the country was filled with water. Now all the Moabites heard that the kings had come up to fight against them. And all who were able to put on armor and older were summoned and stood on the border. They rose early in the morning, and the sun shone on the water, and the Moabites saw the water opposite them as red as blood. Then they said, “This is blood; the kings have surely fought together, and they have slain one another. Now therefore, Moab, to the spoil!” But when they came to the camp of Israel, the Israelites arose and struck the Moabites, so that they fled before them; and they went forward into the land, slaughtering the Moabites.