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:
Read Chapter 3
George Leo Haydock
AD 1849
Blood. The clouds have frequently a reddish colour at sun-rise, which would be reflected in the waters: the sand might also be red. As the Moabites knew that no water could be expected there at that season of the year, and as some examples had occurred of people turning their arms one against another in the night, (Judges vii. 11., and 1 Kings xiv. 20.) they concluded that what they saw was blood. (Calmet)
God had also destined them for slaughter, (Abulensis, q. 21.) and suffered their imagination and judgment to be deluded. (Haydock)