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.

It became a serpent - תנין tannin. What kind of a serpent is here intended, learned men are not agreed. From the manner in which the original word is used in Psa 74:13; Isa 27:1; Isa 51:9; Job 7:12; some very large creature, either aquatic or amphibious, is probably meant; some have thought that the crocodile, a well-known Egyptian animal, is here intended. In Exo 4:3 it is said that this rod was changed into a serpent, but the original word there is נחש nachash, and here תנין tannin, the same word which we translate whale, Gen 1:21.

As נחש nachash seems to be a term restricted to no one particular meaning, as has already been shown on Genesis 3; See Clarke's note on Gen 3:1. So the words תנין tannin, תנינים tanninim, תנים tannim, and תנות tannoth, are used to signify different kinds of animals in the Scriptures. The word is supposed to signify the jackal in Job 30:29; Psa 44:19; Isa 13:22; Isa 34:13; Isa 35:7; Isa 43:20; Jer 9:11, etc., etc.; and also a dragon, serpent, or whale, Job 7:12; Psa 91:13; Isa 27:1; Isa 51:9; Jer 51:34; Eze 29:3; Eze 32:2; and is termed, in our translation, a sea-monster, Lam 4:3. As it was a rod or staff that was changed into the tannim in the cases mentioned here, it has been supposed that an ordinary serpent is what is intended by the word, because the size of both might be then pretty nearly equal: but as a miracle was wrought on the occasion, this circumstance is of no weight; it was as easy for God to change the rod into a crocodile, or any other creature, as to change it into an adder or common snake.

And Moses and Aaron went in unto Pharaoh,.... Into the palace of Pharaoh boldly, and with intrepidity, clothed with such power and authority, and assured of success:

and they did as the Lord had commanded; they demanded in his name the dismission of the children of Israel, and upon his requiring a miracle to confirm their mission, wrought one as follows:

and Aaron cast down his rod before Pharaoh, and it became a serpent: or a "dragon", as the Septuagint version; this word is sometimes used of great whales, Gen 1:21 and of the crocodile, Eze 29:3 and it is very likely the crocodile is meant here, as Dr. Lightfoot (q) thinks; since this was frequent in the Nile, the river of Egypt, where the Hebrew infants had been cast, and into whose devouring jaws they fell, and which also was an Egyptian deity (r). Though no mention is made of Pharaoh's demanding a miracle, yet no doubt he did, as the Lord had intimated he would, and without which it can hardly be thought it would be done; and Artapanus (s), an Heathen writer, expressly asserts it; for he says,"when the king required of Moses to do some sign or wonder, the rod which he had he cast down, and it became a serpent, to the amazement of all, and then took it by its tail and it be came a rod again;''which is a testimony from an Heathen of the truth of this miracle.

(q) Works, vol. 1. p. 702. (r) Crocodylen adorat, Juvenal, Sat. 15. (s) Apud Euseb. Praepar. Evangel. l. 9. c. 27. p. 435.

Aaron cast down his rod before Pharaoh, &c.--It is to be presumed that Pharaoh had demanded a proof of their divine mission.