Exodus 7:18

And the fish that is in the river shall die
Their element being changed, and they not able to live in any other but water:

and the river shall stink;
with the blood, into which it should be congealed, and with the putrefied bodies of fishes floating in it:

and the Egyptians shall loath to drink of the water of the river;
the very colour of it, looking like blood, would set them against it, and create a nausea in them; or "shall be weary" ^F8, tired of drinking it in a little time, through the loathsomeness of it; or be weary in digging about it, ( Exodus 7:24 ) to get some clear water to drink of; or in seeking to find out ways and methods to cure the waters, that so they might be fit to drink of, as Jarchi interprets it.