Matthew Poole and continuators on Exodus 7:22

22 And the Magicians of Egypt did so with their inchantments : and Pharaohs heart was hardened: neither did he hearken unto them, as the LORD had said.

It was not difficult for the Devil to convey bloud speedily and unperceivably and that in great quantity: which might suffice to infect with a bloody colour those small parcels of water which were left for them to shew their art in. Qu. Whence could they have water, when all their waters were turned into blood? Ans. 1. It might be had, either 1. by rain, which at that time God was pleased to send down either for this purpose, or to mitigate the extremity of the plague, or for other reasons known to him though not to us. For that rain sometimes falls in Egypt, though not much, nor often, is affirmed by antient writers, and late travellers. Or 2. from Goshen, which was not far from the Court, or from some houses of the Israelites, who dwelt amongst the Egyptians, as appears from many places of this history, and who were free from these Plagues. See Exod. 8. 22. and 9. 26. and 10. 23. and 12. 13. &c. Or 3. from the pits which they digged. ver. 24. Or 4. from some branch of Nilus, or some vessels in their houses, whose waters were not yet changed: For this change might be wrought not suddenly (which is not affirmed in this relation) but by degrees, which God might so order for this very end, that the Magicians might have matter for the trial of their experiment.

Marginal references: Wisd. 17. [illegible: 1+ letters].