2 Kings 3:20-24

And it happened in the morning about the time of offering the sacrifice, that behold, water came from the direction 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 they took their positions on the border.

Then 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.

So they said, “This is blood; the kings must have fought each other, and they have killed one another. Now then, Moab, to the spoils!”

But when they came to the camp of Israel, the Israelites rose up and struck the Moabites, so that they fled from them; and the Israelites invaded the land, killing the Moabites.