Exodus 7:24 - Exposition

All the Egyptians digged . Not the Hebrews. The water stored in the houses of the Hebrews in reservoirs, cisterns, and the like, was (it would seem) not vitiated; and this would suffice for the consumption of seven days. Water to drink . Blood would not become water by percolation through earth, as Canon Cook appears to think; but there might have been sufficient water in the ground before the plague began, to fill the wells dug, for seven days.