Exodus 7:16 WBT

¹⁴  And the LORD said to Moses, Pharaoh's heart [is] hardened; he refuseth to let the people go.

¹⁵  Go to Pharaoh in the morning; lo, he goeth out to the water, and thou shalt stand by the river's brink against he cometh; and the rod which was turned to a serpent shalt thou take in thy hand.

¹⁶  And thou shalt say to him, The LORD God of the Hebrews hath sent me to thee, saying, Let my people go, that they may serve me in the wilderness: and behold, hitherto thou wouldest not hear.

¹⁷  Thus saith the LORD, In this thou shalt know that I [am] the LORD: behold, I will smite with the rod that [is] in my hand upon the waters which [are] in the river, and they shall be turned to blood.

¹⁸  And the fish that [is] in the river shall die, and the river shall be offensive in smell; and the Egyptians shall lothe to drink of the water of the river.