God had made Pharaoh to be rather afraid of Moses, and though the king had a hard heart, and rebelled against God, he listened to what the two servants of God had to say to him. The people of Egypt were going to learn that those poor slaves that they treated so cruelly, had a Friend greater than their king. their wise men, magicians and armies, and the day was close at hand when the greatness of Egypt would be laid low.
Moses and Aaron went in to Pharaoh, and as the Lord had told them, when he said, “Show a miracle for you,” Aaron threw the rod he carried on ... the ground before Pharaoh, and it became a serpent. Then Pharaoh called for his wise men and magicians, and they threw down their rods which became serpents too, but only Aaron’s serpent had life, and it swallowed the others. But Pharaoh was not willing to listen to Moses and Aaron, though he must have seen the power that was in Aaron’s serpent, the others being only Satan’s imitations—Verse 13 is not correctly translated in our Bibles; there was a time when God hardened Pharaoh’s heart, but it was not this early; here we should read, “And Pharaoh’s heart was hard, that he hearkened not unto them, as the Lord had said.”
Next, the first “plague” fell on Egypt. Because Pharaoh would not hear when he was told that the Lord God of the Hebrews wanted His people let go to .serve Him, Aaron’s rod was used to turn the water of the river into blood. The fish in the river died, and the river stank; the people could not drink the water. But again the magicians imitated; they turned water into blood, too, and Pharaoh was hardened and he would not let the children of Israel go.