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 miracles is now itself the subject of a miracle, to put a reputation upon it. Aaron cast his rod to the ground, and instantly it became a serpent, Exo 7:10. This was proper, not only to affect Pharaoh with wonder, but to strike a terror upon him. Serpents are hurtful dreadful animals; the very sight of one, thus miraculously produced, might have softened his heart into a fear of that God by whose power it was produced. This first miracle, though it was not a plague, yet amounted to the threatening of a plague. If it made not Pharaoh feel, it made him fear; and this is God's method of dealing with sinners - he comes upon them gradually. 3. This miracle, though too plain to be denied, is enervated, and the conviction of it taken off, by the magicians' imitation of it, Exo 7:11, Exo 7:12. Moses had been originally instructed in the learning of the Egyptians, and was suspected to have improved himself in magical arts in his long retirement; the magicians are therefore sent for, to vie with him. And some think those of that profession had a particular spite against the Hebrews ever since Joseph put them all to shame, by interpreting a dream which they could make nothing of, in remembrance of which slur put on their predecessors these magicians withstood Moses, as it is explained, Ti2 3:8. Their rods became serpents, real serpents; some think, by the power of God, beyond their intention or expectation, for the hardening of Pharaoh's heart; others think, by the power of evil angels, artfully substituting serpents in the room of the rods, God permitting the delusion to be wrought for wise and holy ends, that those might believe a lie who received not the truth: and herein the Lord was righteous. Yet this might have helped to frighten Pharaoh into a compliance with the demands of Moses, that he might be freed from these dreadful unaccountable phenomena, with which he saw himself on all sides surrounded. But to the seed of the serpent these serpents were no amazement. Note, God suffers the lying spirit to do strange things, that the faith of some may be tried and manifested (Deu 13:3; Co1 11:19), that the infidelity of others may be confirmed, and that he who is filthy may be filthy still, Co2 4:4. 4. Yet, in this contest, Moses plainly gains the victory. The serpent which Aaron's rod was turned into swallowed up the others, which was sufficient to have convinced Pharaoh on which side the right lay. Note, Great is the truth, and will prevail. The cause of God will undoubtedly triumph at last over all competition and contradiction, and will reign alone, Dan 2:44. But Pharaoh was not wrought upon by this. The magicians having produced serpents, he had this to say, that the case between them and Moses was disputable; and the very appearance of an opposition to truth, and the least head made against it, serve those for a justification of their infidelity who are prejudiced against the light and love of it.

And he hardened Pharaoh's heart - ויחזק לב פרעה vaiyechezak leb Paroh, "And the heart of Pharaoh was hardened," the identical words which in Exo 7:22 are thus translated, and which should have been rendered in the same way here, lest the hardening, which was evidently the effect of his own obstinate shutting of his eyes against the truth, should be attributed to God. See Clarke's note on Exo 4:21.

And he hardened Pharaoh's heart,.... Or, "notwithstanding the heart of Pharaoh was hardened" (a); though he saw the rods of his magicians devoured by rod; or "therefore" (b) his heart was hardened, because he saw that the rods of his magicians became serpents as well as Aaron's; in which there was a deception of sight, and which was suffered for the hardening of his heart, there being other wonders and miracles to be wrought, for showing forth the divine power, before Israel must be let go:

that he hearkened not unto them; to Moses and Aaron, and comply with their demand, to dismiss the people of Israel:

as the Lord had said; or foretold he would not.

(a) "attamen obfirmatum est", Junius & Tremellius. (b) "Itaque", Piscator.

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.