2 Kings 3:22 (KJV)

And it came to pass in the morning, when the meat offering was offered, that, behold, there came water by the way of Edom, and the country was filled with water.

And when all the Moabites heard that the kings were come up to fight against them, they gathered all that were able to put on armour, and upward, and stood in the border.

And they rose up early in the morning, and the sun shone upon the water, and the Moabites saw the water on the other side as red as blood:

And they said, This is blood: the kings are surely slain, and they have smitten one another: now therefore, Moab, to the spoil.

And when they came to the camp of Israel, the Israelites rose up and smote the Moabites, so that they fled before them: but they went forward smiting the Moabites, even in their country.