And the fish in the Nile died, and the Nile stank, so that the Egyptians could not drink water from the Nile. There was blood throughout all the land of Egypt.
Here is the first of the ten plagues, the turning of the water into blood, which was, 1. A dreadful plague, and very grievous. The very sight of such vast rolling streams of blood, pure blood no doubt, florid and high-colored, could not but strike a horror upon people: much more afflictive were the consequences of it.
Commenting on Exodus 7:14-25
And the fish that was in the river died,.... Which was a full proof that the conversion of it into blood was real; for had it been only in appearance, or the water of the river had only the colour of blood, and looked like it, but was not really so, it would not have affected the fishes, they would have lived as well as...
And the fish that [was] in the river died; and the river stank, and the Egyptians could not drink of the water of the river; and there was blood throughout all the land of Egypt. To show that it was a true miracle, God plagued them in that which was most needed for the preservation of life.