Commentary for Exodus 4:3

ויהי לנחש AND IT BECAME A SERPENT — This was an indication to him, that he had slandered the Israelites by saying (v. 1) “But, behold they will not believe me etc.”, and that he had made the serpent’s occupation (slander) his own (cf. Genesis 3:5) (Exodus Rabbah 3:12).

AND HE SAID: CAST IT ON THE GROUND. AND HE CAST IT ON THE GROUND. I do not understand why G-d performed the signs before Moses. Moses believed that it is the Holy One, blessed be He, Who speaks with him, and it would have been fitting for Him to say, “The staff that is in your hand you shall cast on the ground before them, and it shall become a serpent,” and the same also with respect to the second sign, [i.e., his hand becoming leprous], just as He said at the third sign, and thou shalt take of the water of the river, and pour it upon the dry land, etc.²⁵⁵Further, Verse 9. In other words, the third sign of the water turning to blood was not performed now, but only when Moses came before the people. The question thus arises: Why did He perform the first two signs — the staff turning into a serpent, and Moses’ hand becoming leprous — before Moses now? It is for this reason that the words of our Rabbis²⁵⁶Shemoth Rabbah 3:16. can be relied upon, namely, that the first sign, [i.e., the staff turning into a serpent], was a hint to Moses that he had slandered the Israelites [when he said that they would not believe him],²⁵⁷See Genesis 3:5, that the serpent was the first creature to slander when it said to Eve, For G-d doth know that in the day ye eat thereof, ye shall be as G-d, knowing good and evil. Thus it suggested to her that it was not because it may bring about her death that G-d forbade it, but out of a sense of jealousy. As Rashi puts it: “Every artisan detests his fellow-artisans.” and the second sign was for the purpose of punishing him.²⁵⁸See Numbers 12:1-10 that the punishment for slander is leprosy. And this is the sense of the expression, and Moses fled from before it [the serpent]. He feared lest he would be punished and the serpent would bite him, since every person naturally avoids danger, even though Moses knew that if it was indeed G-d’s desire [to punish him], there was no one that could deliver him out of His hand.²⁵⁹See Daniel 8:4.
Perhaps even though He informed Moses of the Great Name with which the world was created and everything came into existence,²⁶⁰See above, 3:13. He wished to show him that with this Name signs and wonders would be done, changing the natural order of things, so that the matter would be firmly established in Moses’ heart and that he should in truth know that with the Great Name he will perform new things in the world. The first two signs were sufficient for Moses, and therefore the third miracle of the water [turning into blood] was not done here. Instead, G-d commanded him to do the third sign in the sight of the people.

וינס משה מפניו, for the staff had become a real snake and had assumed a threatening posture. This was totally different from the “snakes” produced by Pharaoh’s magicians that were unable to move. They only looked like the real thing, but were totally harmless. None of these sorcerers can produce something that is really alive, i.e. becomes part of nature. Our sages in Sanhedrin 67 commented on this phenomenon by saying: “not only can the sorcerers not produce small creatures, they cannot even produce big creatures such as a camel” This is why in the case of Moses, the Torah speaks of “the staff which had turned into a נחש, serpent,” whereas when the sorcerers’ work is described the Torah speaks of תנין. [at that point Aaron’s staff also turned into a תנין, not נחש, as G’d was not yet ready to demonstrate the superior magic Moses was capable of. Only when Aaron’s staff swallowed the “taninim” of the sorcerers was that point brought home to Pharaoh.]