Exodus 7:16-18

Darby Translation

¹⁶ And say unto him, Jehovah the God of the Hebrews has sent me to thee, saying, Let my people go, that they may serve me in the wilderness; but behold, hitherto thou hast not hearkened.

¹⁷ Thus saith Jehovah: In this shalt thou know that I am Jehovah—behold, I will smite with the staff that is in my hand upon the water which is in the river, and it shall be turned into blood.

¹⁸ And the fish that is in the river shall die; and the river shall stink; and the Egyptians shall loathe to drink the water out of the river.