Exodus 7:16-25

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.
24 And all the Egyptians dug round about the river, so as to drink water, for they could not drink water from the river.
25 and seven days were fulfilled after the Lord has smitten the river.

Exodus 7:16-25 Meaning and Commentary

INTRODUCTION TO EXODUS 7

Moses and Aaron are ordered to go to Pharaoh, and require the dismission of the people of Israel, but they are told before hand that Pharaoh's heart would be hardened, and would refuse to let them go, until the hand of the Lord was stretched out, and great judgments were brought down upon, Egypt, and then they should come forth, Ex 7:1-5, which orders Moses and Aaron obeyed, and their age is observed, when this was done, Ex 7:6,7 and they are bid to work a miracle, when Pharaoh should demand one, by turning a rod into a serpent, which they did; but Pharaoh's magicians doing the same in appearance, his heart was hardened, Ex 7:8-14 and then they are directed to meet him at the river, and require the same as before; and if he refused, to smite the waters of the river with the rod, and turn them into blood, which they did, Ex 7:15-21, but Pharaoh's magicians doing the same by enchantments, he did not regard it, though the plague lasted seven days, Ex 7:22-25.

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