Exodus 7:19

“And the Lord spake unto Moses, etc.] Pharaoh still being obstinate, and refusing to let the people go: say unto Aaron, take thy rod, and stretch out thine hand upon the waters of Egypt; upon all of them in general, what were in the river Nile, or derived from it, as follows: upon their streams; the seven streams of the river Nile, ((see Gill on “<231115>Isaiah 11:15”)). upon their rivers; the canals that were cut out of the river Nile, for the watering of their fields and gardens, for they had no other river: and upon their ponds, and upon all their pools of waters; which were dug near the river, or to which pipes were laid to convey the water thither: that they may become blood; and so not…”

“The “streams” mean the natural branches of the Nile in Lower Egypt. The word “rivers” should rather be “canals”; they were of great extent, running parallel to the Nile, and communicating with it by sluices, which were opened at the rise, and closed at the subsidence of the inundation. The word rendered “ponds” refers either to natural fountains, or more probably to cisterns or tanks found in every town and village. The “pools”, literally “gathering of waters,” were the reservoirs, always large and some of enormous extent, containing sufficient water to irrigate the country in the dry season. In vessels of wood - The Nile water is kept in vessels and is purified for use by filtering, and by…”

“stretch: Exo 8:5, Exo 8:6, Exo 8:16, Exo 9:22, Exo 9:23, Exo 9:33, Exo 10:12, Exo 10:21, Exo 14:21, Exo 14:26 their pools: Heb. gathering of their waters, Gen 1:10 Exodus 7:20”