Commentary: On Exodus

If you will surely listen to the voice of the Lord your God and do that which is right in His eyes and give ear to His commandments and observe all His statutes, all the diseases that I have placed upon the Egyptians I will not place upon you, for I am the Lord who heals you. (Exodus 15:26)

That is, [I am the One] who makes you wise and teaches you the right path to follow to avoid disease. This is like a doctor who instructs his friend, “Do not eat this food, do not drink that drink, do not lie in a damp spot, and you will thereby avoid illness.” Here too, if you will surely listen to the voice [of the Lord your God] and do that which is right in His eyes [and give ear to His commandments and observe all His statutes, all the diseases that I have] placed upon the Egyptians (Exodus 15:26)—because the Egyptians did not listen, as it is stated: Who is the Lord that I should listen to His voice? (Exodus 5:2)—I will not place upon you.

And if I do place them, it will be as though they were not placed upon you, for I am the Lord who heals you. This is the midrashic interpretation of the verse.

Its plain meaning [peshat] is: “I am the doctor who warns you not to eat anything that would cause a sick person to relapse into his illness.” This advice is to give ear to the commandments and observe the statutes. [ . . . ]

[And it came to pass, when Moses held up his hand,] Israel prevailed; [and when he let down his hand, Amalek prevailed.] (Exodus 17:11)

This can be explained in accordance with its plain meaning. For when a person holds aloft the flag, which is called fanon in the vernacular [i.e., French], as long as he is holding it, it is a good sign, and they should assist him, for it gives his side the strength to wage war. However, when he lowers it, they will think that they are already beaten and that this is a signal for them to take flight.