It is stated in Parashat Beshalach (Exodus 14:16): "And you lift up your staff and stretch out your hand over the sea and divide it, and the Children of Israel will come into the midst of the sea on dry land." This implies that the splitting of the Red Sea was done, like the other ten plagues, using the staff. Indeed, in the Midrash, they learned from the language of this verse the exact opposite. This is the language of the Midrash (Shemot Rabbah, Parasha 21, Siman 9): Rabbi Simon said, an analogy to a governor [meaning, the person in charge of the state, with a rod of authority in his hand to reprimand all wrongdoers. Etz Yosef] who was walking outside with the rod in his hand. They said, if it weren't for the rod in his hand, he would not be respected [meaning, they said that he isn't respected for who he is, but out of fear of his rod of discipline, they respect him. There]. The king heard and said to him, remove the rod from you and go outside, and anyone who does not greet you, I will take his head. So the Egyptians said, Moses couldn't have done anything without the staff [meaning, they thought that the miracles Moses performed weren't because of his attachment to Hashem, but through magic and sorcery with the staff. There]. When the Israelites came into the sea and the Egyptians were standing behind them, the Holy One, Blessed be He, said to Moses, throw away your staff, so that they won't say that without the staff, he couldn't split the sea, as it is said, 'lift up your staff'. Thus, according to the Midrash, the meaning of lifting the staff mentioned here is not like the stretching of the staff or the lifting of the hand with the staff mentioned in the plagues of Egypt, where it implied that the plague was executed through and by the staff. But the lifting of the staff mentioned here means casting it aside and neglecting to use it. And it must be understood why specifically at the splitting of the sea, this need arose to show the Egyptians that it was not the staff that struck them but the word of Hashem through Moses His servant, a need that was not required until now in all ten plagues.