Matthew Henry on Exodus 7:8-13
The first time that Moses made his application to Pharaoh, he produced his instructions only; now he is directed to produce his credentials, and does accordingly. 1. It is taken for granted that Pharaoh would challenge these demandants to work a miracle, that, by a performance evidently above the power of nature, they might prove their commission from the God of nature. Pharaoh will say, Show a miracle; not with any desire to be convinced, but with the hope that none will be wrought, and then he would have some colour for his infidelity. 2. Orders are therefore given to turn the rod into a serpent, according to the instructions, Exo 4:3. The same rod that was to give the signal of the other…
Read the whole note in the consoleJamieson-Fausset-Brown on Exodus 7:12
but Aaron's rod swallowed up their rods--This was what they could not be prepared for, and the discomfiture appeared in the loss of their rods, which were probably real serpents.
Adam Clarke on Exodus 7:12
Aaron's rod swallowed up their rods - As Egypt was remarkably addicted to magic, sorcery, etc., it was necessary that God should permit Pharaoh's wise men to act to the utmost of their skill in order to imitate the work of God, that his superiority might be clearly seen, and his powerful working incontestably ascertained; and this was fully done when Aaron's rod swallowed up their rods. We have already seen that the names of two of the chief of these magicians were Jannes and Jambres; see Clarke on Exo 2:10 (note), and Ti2 3:8 (note). Many traditions and fables concerning these may be seen in the eastern writers.
John Gill on Exodus 7:12
For they cast down every man his rod, and they became serpents,.... That is, they seemed to be so, as Josephus (z) expresses it, but not really, in which he is followed by many; though some think that the devil assisted in this affair, and in an instant, as soon as the rods were cast down, removed them and put real serpents in their room:
but Aaron's rod swallowed up their rods; that is, the serpent that Aaron's rod was turned into, swallowed up the rods of the magicians, which never were otherwise than rods only in appearance; or if real serpents were put in the room of them, these were devoured by his serpent called his rod, because it was before turned into a serpent, as Aben Ezra observ…