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 Psalm 74:13; Isaiah 27:1; Isaiah 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 Exodus 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, Genesis 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 Genesis 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; Psalm 44:19; Isaiah 13:22; Isaiah 34:13; Isaiah 35:7; Isaiah 43:20; Jeremiah 9:11, etc., etc.; and also a dragon, serpent, or whale, Job 7:12; Psalm 91:13; Isaiah 27:1; Isaiah 51:9; Jeremiah 51:34; Ezekiel 29:3; Ezekiel 32:2; and is termed, in our translation, a sea-monster, Lamentations 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, Genesis 1:21 and of the crocodile, Ezekiel 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.

And Moses and Aaron went in unto Pharaoh, and they did so as the LORD had commanded: and Aaron cast down his rod before Pharaoh, and before his servants, and it became a serpent.

7:10 And Aaron cast his rod down, and it became a serpent - This was proper not only to affect Pharaoh with wonder, but to strike a terror upon him. 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; this is God's method of dealing with sinners he comes upon them gradually.

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

7:8-13 What men dislike, because it opposes their pride and lusts, they will not be convinced of; but it is easy to cause them to believe things they wish to be true. God always sends with his word full proofs of its Divine authority; but when men are bent to disobey, and willing to object, he often permits a snare to be laid wherein they are entangled. The magicians were cheats, trying to copy the real miracles of Moses by secret sleights or jugglings, which to a small extent they succeeded in doing, so as to deceive the bystanders, but they were at length obliged to confess they could not any longer imitate the effects of Divine power. None assist more in the destruction of sinners, than such as resist the truth by amusing men with a counterfeit resemblance of it. Satan is most to be dreaded when transformed into an angel of light.