(1) But Moses spoke up and said, “What if they do not believe me and do not listen to me, but say: The Lord did not appear to you?”
(2) The Lord said to him, “What is that in your hand?” And he replied, “A rod.”
(3) He said, “Cast it on the ground.” He cast it on the ground and it became a snake; and Moses recoiled from it.
(4) Then the Lord said to Moses, “Put out your hand and grasp it by the tail” — he put out his hand and seized it, and it became a rod in his hand —
(5) “that they may believe that the Lord, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, did appear to you“.
(1) But Moses spoke up and said, “What if they do not believe me and do not listen to me, but say: The Lord did not appear to you?”: But later, verse 31 states clearly that “the people were convinced” (literally, “the people believed”). Thus, Moses’ fears here were exaggerated.
Moreover, when in the wilderness Moses smites the rock with his staff in order to extract water from it (rather than just speaking to the rock, as God had commanded him to do), the Torah relates (Num. 20:12): “But the Lord said to Moses and Aaron, ‘Because you did not trust Me enough’ ” (literally, “because you did not believe in Me”). To which the Midrash adds: “The Jews, who Moses before the Exodus had feared would not believe him, did in fact believe. But Moses himself lacked faith at the moment when he smote the rock.”
In other words, the problem of insufficient faith lies with Moses, not with the people! We will examine more closely the issue of faith (and the lack thereof) in our commentary on the aforementioned verse of Numbers.
Moses expresses doubt that there is any hope of persuading the Jews, but in reality he cannot possibly predict what the people will say, and his repeated refusals are rooted in his own self-doubts regarding the mission proposed to him. The signs that the Almighty will now show Moses are therefore needed, first and foremost, not as a set of magical formulas for convincing the people, but for explicating the Exodus mission itself.
The purpose of the three signs that God is about to show Moses is to change, both for Moses and for the people to whom Moses will have to show these signs, the way they view the entire undertaking of the Exodus.
(2) The Lord said to him, “What is that in your hand?” And he replied, “A rod”: The lesson begins with Moses acknowledging his own status as a leader. Although the staff in a practical sense is simply the sign of his work as a shepherd, it is now also a symbol of Moses’ power and his leadership of the people.
(3-4) He said, “Cast it on the ground.” He cast it on the ground and it became a snake; and Moses recoiled from it. Then the Lord said to Moses, “Put out your hand and grasp it by the tail” — he put out his hand and seized it, and it became a rod in his hand: The serpent is a prominent symbol in Egyptian culture. The Pharaohs placed on their foreheads a Uraeus, which is a figurine of a serpent. But a serpent coils itself into a round shape, while a staff is always straight.
In this sign, Moses first holds in his hand a straight object. So long as he keeps it in his hand it remains straight – it is subordinated to him. But when Moses casts it to the ground, it becomes round, and also deadly, such that Moses must even “recoil” (literally, “flee”) from it. But then Moses finds that he is able to seize the snake by the tail, and it again becomes straight.
In the Kabbalah, roundness is understood as representing nature, which remains constant in every direction. That is, the laws of nature have no purpose or direction of their own (which is what the serpent symbolizes).
But straightness, on the other hand, represents morality – Providence, Divine control of the world, which has a definite purpose and direction. Thus, the transformations here of staff to serpent and back again, between straightness and roundness, should be understood as the Almighty’s commentary to Moses on the relationship of morality to nature.
Thrown to the ground, taken from the hand of man, from civilization, the staff (which represents control) returns to nature by becoming a snake. Moses then flees from it, from the natural world that is alien to him. Moses’ space is the wilderness, in which there is little if any “animated life,” where God’s voice dominates. But the Almighty tells Moses that there is no need to flee from nature; that is, from Egypt in all its naturalness. Simply grab the snake by the tail, and it will again become a staff.
Moses yearns for the giving of the Torah, the gift of the Law from Above; not natural laws, but supernatural, transcendental teachings. But for the proper advancement of the world, unification of the Divine teachings with the natural world must occur. We should not be trying to escape from the natural world; rather, we must “grab the snake (nature) by its tail,” so that nature becomes morality – a staff that guides the life of the people. The staff of morality is effective only when it arises from the serpent of nature seized by the tail.
(5) That they may believe that the Lord, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, did appear to you: This approach reinforces Moses’ connection with the Patriarchs, because the Patriarchs built their Divine teachings based on converting nature to morality, and not on the idea of a transcendental Divine Law descended from Heaven (which is what Moses values most). Thus, by giving Moses this sign God is saying: “That they may believe that the Lord, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, did appear to you. If you yourself will feel it, then they too will believe you.”
Moses’ power over the serpent that he seizes will serve as evidence to the Jews that God has sent Moses to defeat Egypt.
 This also applies to the serpent in the story of the Garden of Eden (Gen. 3).