Exodus 7:13-15

King James Version

¹³ And he hardened Pharaoh's heart, that he hearkened not unto them; as the Lord had said.

¹⁴ And the Lord said unto Moses, Pharaoh's heart is hardened, he refuseth to let the people go.

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