(19) The waters of Egypt consist of the main stream of the Nile; its branches; canals derived from it; natural lakes, pools, or ponds, either left by the inundation or anticipative of it, being derived by percolation from the main stream; and artificial reservoirs of a larger or smaller size in gardens, courts, and houses. There is no other stream but the Nile in the whole country; and there are no natural springs, fountains, or brooks. Water may, however, at all times, and in all parts of the Nile Valley, be obtained by digging wells; but, as the soil is impregnated with nitre, the well water is highly unpalatable. It is generally allowed that the author of Exodus shows in the present verse, coupled with Exodus 7:24, a very exact knowledge of the Egyptian water system.

Vessels of wood, and vessels of stone.--It was usual to store the Nile water in tanks or cisterns within the houses, in order that it might deposit its sediment. These tanks or cisterns, which existed in all the houses of the better class, were either of wood or stone.

Verse 19. - Say unto Aaron. There is an omission here (and generally throughout the account of the plagues) of the performance by Moses of God's behest. The Samaritan Pentateuch in each case supplies the omission. It has been argued (Kennicott) that the Hebrew narrative has been contracted; but most critics agree that the incomplete form is the early one, and that, in the Samar. version, the original narrative has been expanded. The waters of Egypt... streams... rivers... ponds... pools of water. The waters of Lower Egypt, where this miracle was wrought, consisted of

(1) the various branches of the Nile, natural and artificial, which were seven when Herodotus wrote (Herod. 2:17), whence the Nile was called "septemfluus," or "septemgeminus;"

(2) the canals derived from each branch to fertilise the lands along its banks;

(3) ponds, marshes, and pools, the results of the overflowing of the Nile, or of its percolation through its banks on either side; and

(4) artificial reservoirs, wherein water was stored for use after the inundation was over. The four terms of the text seem applicable to this four-fold division, and "show an accurate knowledge of Egypt" (Cook), and of its water system. The "streams" are the Nile branches; the" rivers correspond to the canals; the "ponds" are the natural accumulations of waters in permanent lakes or in temporary pools and marshes; while the "pools," or "gatherings of waters" (margin), are the reservoirs made by art. Aaron was to stretch out his rod over the Nile, but with the intent to smite all the Egyptian waters, and all the waters would at once be smitten, the streams and the canals and the natural lakes and the reservoirs. The miracle would even extend to private dwell-trigs, and the change would take place throughout all the land of Egypt, not only in respect of the open waters spread over the country, but even in respect of that stored, as was usual, in houses, and contained either in vessels of wood or in vessels of stone. With respect to these, it is to be observed that the Nile water was much improved by keeping, since the sediment subsided; and that tanks, sometimes of wood, sometimes of stone, were usual adjuncts of all the better class of houses.

7:14-25 Here is the first of the ten plagues, the turning of the water into blood. It was a dreadful plague. The sight of such vast rolling streams of blood could not but strike horror. Nothing is more common than water: so wisely has Providence ordered it, and so kindly, that what is so needful and serviceable to the comfort of human life, should be cheap and almost every where to be had; but now the Egyptians must either drink blood, or die for thirst. Egypt was a pleasant land, but the dead fish and blood now rendered it very unpleasant. It was a righteous plague, and justly sent upon the Egyptians; for Nile, the river of Egypt, was their idol. That creature which we idolize, God justly takes from us, or makes bitter to us. They had stained the river with the blood of the Hebrews' children, and now God made that river all blood. Never any thirsted after blood, but sooner or later they had enough of it. It was a significant plague; Egypt had great dependence upon their river, Zec 14:18; so that in smiting the river, they were warned of the destruction of all the produce of their country. The love of Christ to his disciples changes all their common mercies into spiritual blessings; the anger of God towards his enemies, renders their most valued advantages a curse and a misery to them. Aaron is to summon the plague by smiting the river with his rod. It was done in the sight of Pharaoh and his attendants, for God's true miracles were not performed as Satan's lying wonders; truth seeks no corners. See the almighty power of God. Every creature is that to us which he makes it to be water or blood. See what changes we may meet with in the things of this world; what is always vain, may soon become vexatious. See what mischievous work sin makes. If the things that have been our comforts prove our crosses, we must thank ourselves. It is sin that turns our waters into blood. The plague continued seven days; and in all that time Pharaoh's proud heart would not let him desire Moses to pray for the removal of it. Thus the hypocrites in heart heap up wrath. No wonder that God's anger is not turned away, but that his hand is stretched out still.And the Lord spake unto Moses,.... 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 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 fit to drink:

and that there may be blood throughout all the land of Egypt,

both in vessels of wood, and in vessels of stone; in which water were kept in private houses, fetched from the river for the use of families; all which were to be turned into blood everywhere, in all parts of the land, and in all places mentioned, immediately upon Aaron's taking his rod, and smiting the waters with it in that part of the river that was before him.