Exo 7:22 | JFB | STEP | 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.

‏ Exodus 7:22

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.