Exodus 7:13-23

13 and the heart of Pharao was hardened, and he hearkened not to them, as the Lord charged them.
14 and the Lord said to Moses, The heart of Pharao is made hard, so that he should not let the people go.
15 Go to Pharao early in the morning: behold, he goes forth to the water; and thou shalt meet him on the bank of the river, and thou shalt take in thine hand the rod that was turned into a serpent.
16 And thou shalt say to him, The Lord God of the Hebrews has sent me to thee, saying, Send my people away, that they may serve me in the wilderness, and, behold, hitherto thou hast not hearkened.
17 These things saith the Lord: Hereby shalt thou know that I am the Lord: behold, I strike with the rod that is in my hand on the water which is in the river, and it shall change it into blood.
18 And the fish that are in the river shall die, and the river shall stink thereupon, and the Egyptians shall not be able to drink water from the river.
19 And the Lord said to Moses, Say to thy brother Aaron, Take thy rod in thy hand, and stretch forth thy hand over the waters of Egypt, and over their rivers, and over their canals, and over their ponds, and over all their standing water, and it shall become blood: and there was blood in all the land of Egypt, both in vessels of wood and of stone.
20 and Moses and Aaron did so, as the Lord commanded them; and having lifted up with his rod, smote the water in the river before Pharao, and before his servants, and changed all the water in the river into blood.
21 And the fish in the river died, and the river stank thereupon; and the Egyptians could not drink water from the river, and the blood was in all the land of Egypt.
22 And the charmers also of the Egyptians did so with their sorceries; and the heart of Pharao was hardened, and he did not hearken to them, even as the Lord said.
23 And Pharao turned and entered into his house, nor did he fix his attention even on this thing.

The Brenton translation of the Septuagint is in the public domain.