Exo 7:10 So Moses and Aaron went to Pharaoh and did just as the LORD commanded. Aaron cast down his staff before Pharaoh and his servants, and it became a serpent.
Exo 7:11 Then Pharaoh summoned the wise men and the sorcerers, and they, the magicians of Egypt, also did the same by their secret arts.
Exo 7:12 For each man cast down his staff, and they became serpents. But Aaron's staff swallowed up their staffs.
All the plagues God did through Moses and Aaron in delivering Israel from Pharaoh were in part also directed against the gods that the Egyptians trusted in rather than bowing before the True and Living God. The first miracle before Pharaoh in the verses above is no exception. The serpent was considered a wise and magical creature in Egypt. Wadjet, who was the goddess of Lower Egypt, is represented as a snake. It was her symbol which is found on the crown of the Egyptian Pharaoh. Once upon a time, Upper Egypt and Lower Egypt were separate countries. Lower Egypt was eventually captured by Upper Egypt, and when that happened the Pharaoh assimilated the goddess of Lower Egypt into his own crown. And so that symbol became a sign of Pharaoh’s sovereignty and power. But additionally it is interesting that Apopis, who is an enemy of the gods in Egyptian mythology, is often pictured in the form of a snake, and it represents the forces of chaos arraigned against Egypt. Clearly then, in the throwing down of this rod snake, God, the Lord of Israel, is challenging the gods of Egypt. The Lord is challenging Pharaoh’s authority; he’s mocking his magic.
Swallowing was important to the Egyptians because they believed that to swallow something caused one to acquire all its powers. This probably wasn’t lost on the magicians since in 8:19 when they could no longer duplicate the miracles they knew that the true God was at work, Exo 8:19 Then the magicians said to Pharaoh, "This is the finger of God." But Pharaoh's heart was hardened, and he would not listen to them, as the LORD had said.
It is no mere coincidence that Satan is depicted as a snake and with a purpose God has Aaron’s rod turn into a snake because this whole account reminds us of the greater exodus when God’s appointed Messiah delivered the elect from the Prince and Power of the air and the death that comes with it. Christ was depicted as a snake on the cross because he took the curse of sin on himself and became a curse for us.
The exodus is God’s greatest miracle in this book. It pictures God’s greatest work in sending his Son to atone for sins. From the time he came into the world Satan used his limited power to try and destroy him. He sent his servants to try and kill him and tempt him and bring his mission to nothing. But in each case God swallowed up their attempts and triumphed over them. Satan’s biggest mistake was to put it into men’s hearts to crucify Jesus. In doing that, death, our greatest enemy was what? It was swallowed up in the victory of the resurrection! 1Co 15:54 When the perishable puts on the imperishable, and the mortal puts on immortality, then shall come to pass the saying that is written: "Death is swallowed up in victory." 1Co 15:55 "O death, where is your victory? O death, where is your sting?" God’s snake swallowed Satan’s snake.
Paul explains a little differently in Col 2:14 by canceling the record of debt that stood against us with its legal demands. This he set aside, nailing it to the cross. Col 2:15 He disarmed the rulers and authorities and put them to open shame, by triumphing over them in him.
The day Moses and Aaron stood before Pharaoh and his magicians and their snake swallowed up their snake and put them to open shame would have been a sight to behold and even more to be outside the tomb when Jesus defeated death in his resurrection would be an amazing sight. But the Exodus account ends with a bit of a warning, Exo 7:13 Still Pharaoh's heart was hardened, and he would not listen to them, as the LORD had said. Pharaoh didn’t see or acknowledge the glory of God in the miracle and most today can’t see the glory of God in the Gospel of Christ where he swallowed up the works of sin and Satan. They, like Pharaoh, harden their heart to their own destruction. It is the grace of God alone that enables us to see what the lost cannot. To God be all the glory for our salvation.