22. And the magicians . . . did so with their enchantments, &c.--Little or no pure water could be procured, and therefore their imitation must have been on a small scale --the only drinkable water available being dug among the sands. It must have been on a sample or specimen of water dyed red with some coloring matter. But it was sufficient to serve as a pretext or command for the king to turn unmoved and go to his house.
JFB.
Picture Study Bible