“The Lord said to him further: Put your hand in your bosom. He put his hand in his bosom and took it out, and behold, his hand was leprous, like snow” (Exodus 4:6). “The Lord said to him further: Put your hand in your bosom.” He said to him: ‘It is just like the serpent who, when he engaged in slander, I afflicted him with leprosy, as it is stated: “Cursed [arur] are you from all the animals” (Genesis 3:14), as you say: “Malignant [mameret] leprosy”’ (Leviticus 13:51).
Rabbi Elazar said: Those spots on it [the serpent] are leprous marks; so do you deserve to be afflicted with leprosy. Why did he place it in his bosom? It is because slander is typically told in secret. Likewise it says: “He who slanders his neighbor in secret, I will destroy [atzmit]” (Psalms 101:5).
Atzmit [refers to] nothing but leprosy, as it is stated: “In perpetuity [litzmitut]” (Leviticus 25:23), which is translated as completely [laḥalutin]29In Targum Onkelos. and it is taught: “The difference between a quarantined leper and a confirmed leper [muḥlat] is only… (Megilla 8b).”30The midrash cites the mishna to show that the word muḥlat, which is derived from the same root as laḥalutin, is used in the context of leprosy.
“He put his hand in his bosom and took it out, and behold, his hand was leprous, like snow.” He received his due because he engaged in slander. Rabbi Yehoshua of Sikhnin said in the name of Rabbi Levi: From here you learn that anyone who suspects another of something which is untrue of him, is afflicted in his body. “He said: Put your hand back in your bosom.
He put his hand back in his bosom; and he removed it from his bosom, and behold, it was restored like his flesh” (Exodus 4:7). “He said: Put your hand back in your bosom.” How is there a sign for Israel in this? [It is as if God were saying:] Go and say to them: Just as a leper causes impurity, so do the Egyptians render you impure. And just as he [the leper] is purified, so is the Holy One blessed be He destined to purify Israel, as it is written: “And behold, his hand was leprous, like snow,” and in the healing it is written: “He removed it from his bosom, and behold, it was restored like his flesh.”
Our Rabbis say: So as not to cast aspersions on Moses’s flesh [i.e. his bosom]; therefore, his hand was not afflicted with leprosy until he removed it from his bosom. However, regarding the healing, it was healed in his bosom. Alternatively, from here punishments are delayed before being exacted upon the righteous, while the [divine] attribute of goodness takes effect quickly. “And it shall be that if they do not believe even these two signs, and they do not heed your voice, you shall take from the water of the Nile and pour it out on dry land; and the water that you take from the Nile will become blood on the dry land” (Exodus 4:9).
“It will be, if they will not believe even these two…” Why did the Holy One blessed be He perform three signs for him? It is corresponding to Abraham, Isaac, and Jacob. “You shall take from the water of the Nile.” He indicated to him that, by means of something he will say to Israel, the water is destined to be transformed into blood, and he will be punished through it [the water], as it is written: “Hear now, defiant ones” (Numbers 20:10), and he struck the stone and extracted [water], as it is stated: “Behold, He struck the rock, and water flowed out [vayazuvu]” (Psalms 78:20).
Vayazuvu is an expression of nothing other than blood, as it is stated: “If a woman will have a flow [yazuv zov] of her blood” (Leviticus 15:25). That is why he struck the stone twice, as initially it produced blood and finally water. In the first two signs, you find that they were restored to their original state, but the sign of the blood was not restored to its original state because He did not wish to forgive Moses for the sin of the water. And how was there a sign for Israel in this? He said to them: ‘With this sign the Egyptians will be afflicted first.’