"From here, Rabbi Yehuda HaLevi bar Rabbi Shalom said: Leprosy comes due to eleven matters: For cursing the name of God, for illicit sexual relations, for bloodshed, for saying regarding another a [negative] matter that is not accurate, for arrogance, for one who enters an area that is not his, for false speech, for thefts, for a false oath, for one who profanes the name of Heaven, and for idol worship. Rabbi Yitzḥak says: For miserliness. Our Rabbis say: For one who scorns matters of Torah.
According to the opinion of the Rabbis, who said: For one who scorns matters of Torah, it is as it is stated: “Therefore, as a tongue of fire consumes straw [and a flame destroys chaff]…their blossom [ufirḥam] will rise as dust; [for they spurned the Torah of the Lord of hosts and scorned the word of the Holy One of Israel]” (Isaiah 5:24). This is leprosy, as it is stated: “If the leprosy shall erupt [paro’aḥ tifraḥ]” (Leviticus 13:12). What is “will rise as dust”? It is like that furnace soot that Moses cast heavenward: “It will become dust over the entire land of Egypt” (Exodus 9:9) – from it the Egyptians were stricken with “a rash erupting in blisters on man and on animal” (Exodus 9:10).
According to the opinion of Rabbi Yitzḥak, who said: For miserliness, when a person is miserly and does not lend his utensils, the Holy One blessed be He will afflict his house with leprosy; he takes his utensils outside, and the people say: So-and-so, who would not lend his utensils and would say that he did not have utensils, he did have utensils. In his regard the verse states: “The produce of his house will be exiled” (Job 20:28).
According to the opinion of Rabbi Yehuda HaLevi, who said: For cursing the name of God, he derives it from Goliath, as it is stated: “For he blasphemed the armies of the living God” (I Samuel 17:36). What is written in his regard? “This day, the Lord will deliver you [yesagerkha] into my hand” (I Samuel 17:46). “Yesagerkha” is nothing other than leprosy, as it is stated: “The priest shall quarantine him [vehisgiro]” (Leviticus 13:5).
For illicit sexual relations, from where is it derived? It is as it is stated: “The Lord will afflict with scabs [vesipaḥ] the heads of the daughters of Zion” (Isaiah 3:17). Rabbi Elazar ben Pedat said: Vesipaḥ is nothing other than leprosy, as it is stated: “A spot or a scab [sapaḥat]…” (Leviticus 13:2).
For bloodshed, from Cain, as it is stated: “God placed a mark [ot] on Cain” (Genesis 4:15). Rabbi Neḥemya said: This is leprosy. “Ot” is stated here, and “ot” (II Kings 20:8) is stated regarding Hezekiah. Just as ot stated regarding Hezekiah was a rash, so, too, here, it is a rash. If you do not derive it, derive it from Yoav, who shed blood. What is written in his regard? “May there not be eliminated from the house of Yoav a zav or a leper” (II Samuel 3:29).
For saying regarding another a [negative] matter that is not accurate, this is [from] Moses, as when God said to him that he should go to Israel, he said to Him: ‘My Master, but they will not believe me,’ as it is stated: “But they will not believe me…” (Exodus 4:1). God said to him: ‘Moses, do you already know that they will not believe you? They are believers, descendants of believers, yet you say to Me, “but they will not believe me…”?’ “Bring your hand to your bosom…” (Exodus 4:6). Immediately, “he withdrew it, and behold, his hand was leprous like snow (Exodus 4:6).
For arrogance, this is Naaman, as it is stated: “Naaman, commander of the army of the king of Aram, was a great man […and the man…was leprous]” (II Kings 5:1). What is “great”? It is that he had an arrogance of spirit because he was a great warrior. It is due to this that he was afflicted with leprosy.
For one who enters an area that is not his, this is Uziyahu, who sought to enter the area of the priesthood. What is written in his regard? “The leprosy radiated on his forehead” (II Chronicles 26:19).
For false speech, this is Miriam, as it is stated: “Miriam and Aaron spoke against Moses” (Numbers 12:1). What is written thereafter? “Aaron turned to Miriam, and behold, she was leprous” (Numbers 12:10).
For thefts and for a false oath, as it is written: “It will arrive at the house of the thief and at the house of one who takes an oath by My name falsely, […and it will eliminate it and its timber and its stones]” (Zechariah 5:4). What is a plague that destroys timber and stones? This is leprosy, as it is stated: “He shall demolish the house, its stones, and its timber…” (Leviticus 14:45)."