(1) The LORD spoke to Moses, saying: (2) This shall be the instruction for a leper at the time that he is to be purified, He shall be brought to the priest...
Reish Lakish says: What is the meaning of that which is written: “This shall be the Torah of the leper [metzora] in the day of his cleansing: He shall be brought to the priest” (Leviticus 14:2)? This means that this shall be the law of a defamer [motzi shem ra].
הַצָּרַעַת הוּא שֵׁם הָאָמוּר בְּשֻׁתָּפוּת כּוֹלֵל עִנְיָנִים הַרְבֵּה שֶׁאֵין דּוֹמִין זֶה לָזֶה. שֶׁהֲרֵי לֹבֶן עוֹר הָאָדָם קָרוּי צָרַעַת. וּנְפִילַת קְצָת שְׂעַר הָרֹאשׁ אוֹ הַזָּקָן קָרוּי צָרַעַת. וְשִׁנּוּי עֵין הַבְּגָדִים אוֹ הַבָּתִּים קָרוּי צָרַעַת. וְזֶה הַשִּׁנּוּי הָאָמוּר בַּבְּגָדִים וּבַבָּתִּים שֶׁקְּרָאַתּוּ תּוֹרָה צָרַעַת בְּשֻׁתָּפוּת הַשֵּׁם אֵינוֹ מִמִּנְהָגוֹ שֶׁל עוֹלָם אֶלָּא אוֹת וּפֶלֶא הָיָה בְּיִשְׂרָאֵל כְּדֵי לְהַזְהִירָן מִלָּשׁוֹן הָרַע. שֶׁהַמְסַפֵּר בְּלָשׁוֹן הָרַע מִשְׁתַּנּוֹת קִירוֹת בֵּיתוֹ. אִם חָזַר בּוֹ יִטְהַר הַבַּיִת. אִם עָמַד בְּרִשְׁעוֹ עַד שֶׁהֻתַּץ הַבַּיִת מִשְׁתַּנִּין כְּלֵי הָעוֹר שֶּׁבְּבֵיתוֹ שֶׁהוּא יוֹשֵׁב וְשׁוֹכֵב עֲלֵיהֶן. אִם חָזַר בּוֹ יִטְהֲרוּ. וְאִם עָמַד בְּרִשְׁעוֹ עַד שֶׁיִּשָּׂרְפוּ מִשְׁתַּנִּין הַבְּגָדִים שֶׁעָלָיו. אִם חָזַר בּוֹ יִטְהֲרוּ וְאִם עָמַד בְּרִשְׁעוֹ עַד שֶׁיִּשָּׂרְפוּ מִשְׁתַּנֶּה עוֹרוֹ וְיִצְטָרֵעַ וְיִהְיֶה מֻבְדָּל וּמְפֻרְסָם לְבַדּוֹ עַד שֶׁלֹּא יִתְעַסֵּק בְּשִׂיחַת הָרְשָׁעִים שֶׁהוּא הַלֵּיצָנוּת וְלָשׁוֹן הָרַע.
The Hebrew term for leprosy (Tzara'at) [has] various meanings...The whiteness in a man's skin is called leprosy; the falling off of some hair on the head or the chin is named leprosy; and a change of color in clothing or in houses is referred to as leprosy. Now this change in clothes and in houses which the Torah has called leprosy... is not a natural phenomenon, but was deemed a sign and a wonder among the people of Israel to warn them against evil gossip. If a man dealt out malicious gossip, the walls of his house would change; if he repented, the house would become clean again. But if he persisted in his wickedness until the house was demolished, leather objects in his home upon which he would sit or lie would then suffer a change; if he repented, they would become clean again. But if he persisted in his wickedness until they had to be burned, the clothes which he wore would undergo a change; if he repented, they would become clean again. But if he persisted in his wickedness until they had to be burned, his skin would suffer a change and he would become leprous, and be set apart and exposed all alone, so as not to engage in evil talk, which consists of mockery and malicious gossip.
"And Ad-nai said to Moshe... 'When you sell goods to your people [you shall not wrong one another]' (Leviticus 25:1-14)." Another verse: "Life and death and in the hand of the tongue", the translation of Onkelos 'mystromakerion' [an eating utensil, a side is a spoon the other a knife] death from this side and life from this side. Bar Sira said: 'there is a fiery coal in front of him, if he blows on it it catches fire, if he spits he puts it out.' Rabbi Yannai said: if he had a piece of bread in front of him and ate it without tithing, this is 'death by the hand of the tongue'; if he tithed it before eating, this is 'life by the hand of the tongue.' Said Rabbi Chiya bar Abba: If he had a basket of figs. If he ate them before he separated off tithes, then it is death by the hand of the tongue. If he separated off tithes and then ate, it is life by the hand of the tongue. Rabbi Shimon ben Gamliel said to Tavi his servant, "go purchase for me the best food from the market." He went and bought for him a tongue. He said to him "go purchase for me the worse food from the market." He went out and bought him a tongue. He said to him, "What is this? When I say to you to the best food, you buy me a tongue, and when I say to you the worst food, you [also] buy me tongue!" [Tavi] said to him, this is the best and this is the worst! When it is good, there is none better than it, and when it is bad, there is no worse than it." Rabbi made a feast for his students, and brought before them tender tongues and tough tongues. They began to choose for themselves the tender tongues and left alone the tough tongues. He said to them, "Know what you are doing! Just as you are choosing the tender [tongues] and leaving alone the tough ones, so shall your own tongues be with one another. Thefore Moshe warned Israel, 'and when you sell goods... [you shall not wrong one another]'
(ויקרא יג, מה) וטמא טמא יקרא טומאה קוראה לו ואומרת לו פרוש וכן אמר רבי עוזיאל בר בריה דרבי עוזיאל רבה טומאה קוראה לו ואומרת לו פרוש והאי להכי הוא דאתא ההוא מיבעי ליה לכדתניא וטמא טמא יקרא צריך להודיע צערו לרבים ורבים מבקשין עליו רחמים
And he shall cry, Impure! Impure! [That is], impurity cries out [to the passer-by] and tells him: Keep off! And R. Uzziel, the grandson of the elder Rav Uzziel, said the same, [that] impurity cries out [to the passer-by] and tells him: Keep off! (so that person does not come into contact with him and acquire ritual impurity)
But, was this [text] intended for this lesson? It is required for what has been taught: And he shall cry, Unclean! Unclean! [This teaches that] one must make his distress known to many, that many pray for mercy on his behalf.
מִכָּאן אָמַר רַבִּי יְהוּדָה הַלֵּוִי בַּר רַבִּי שָׁלוֹם עַל אַחַד עָשָׂר דְבָרִים הַצָּרַעַת בָּאָה, עַל קִלְלַת הַשֵּׁם, וְעַל גִּלּוּי עֲרָיוֹת, וְעַל שְׁפִיכוּת דָּמִים, וְעַל הָאוֹמֵר עַל חֲבֵרוֹ דָּבָר שֶׁאֵינוֹ בּוֹ, וְעַל גַּסּוּת הָרוּחַ, וְעַל הַנִּכְנָס בִּתְחוּם שֶׁאֵינוֹ שֶׁלּוֹ, וְעַל לְשׁוֹן שֶׁקֶר, וְעַל הַגְּנֵבוֹת, וְעַל שְׁבוּעַת שֶׁקֶר, וְעַל הַמְחַלֵּל שֵׁם שָׁמַיִם, וְעַל עֲבוֹדַת כּוֹכָבִים. רַבִּי יִצְחָק אוֹמֵר עַל עַיִן רָעָה. וְרַבּוֹתֵינוּ אוֹמְרִים עַל מִי שֶׁמְּנַאֵץ בְּדִבְרֵי תוֹרָה...
עַל דַּעְתֵּיהּ דְּרַבִּי יִצְחָק דְּאָמַר עַל עַיִן הָרָע, כְּשֶׁאָדָם צַר עַיִן וְאֵינוֹ מַשְׁאִיל אֶת כֵּלָיו הַקָּדוֹשׁ בָּרוּךְ הוּא מְשַׁלֵּחַ צָרַעַת בְּבֵיתוֹ וּמוֹצִיא כֵּלָיו לַחוּץ וְהַבְּרִיוֹת אוֹמְרִים פְּלוֹנִי שֶׁלֹא הָיָה מַשְׁאִיל כֵּלָיו וְאוֹמֵר שֶׁלֹא הָיוּ לוֹ כֵּלִים, הֲרֵי שֶׁהָיוּ לוֹ כֵּלִים, וְעָלָיו הַכָּתוּב אוֹמֵר (איוב כ, כח): יִגֶל יְבוּל בֵּיתוֹ. ... וְעַל הָאוֹמֵר דָּבָר לַחֲבֵרוֹ שֶׁאֵינוֹ בּוֹ, זֶה משֶׁה, בְּשָׁעָה שֶׁאָמַר לוֹ הָאֱלֹקִים שֶׁיֵּלֵךְ אֵצֶל יִשְׂרָאֵל, אָמַר לוֹ רִבּוֹנִי וַהֲרֵי אֵינָן מַאֲמִינִין אוֹתִי, שֶׁנֶּאֱמַר (שמות ד, א): וְהֵן לֹא יַאֲמִינוּ לִי וגו', אָמַר לוֹ הָאֱלֹקִים הָא משֶׁה כְּבָר אַתְּ יוֹדֵעַ שֶׁאֵינָן מַאֲמִינִין אוֹתָךְ, מַאֲמִינִין בְּנֵי מַאֲמִינִין הֵם, אָמַרְתָּ לִי: וְהֵן לֹא יַאֲמִינוּ לִי וגו' (שמות ד, ו): הָבֵא נָא יָדְךָ בְּחֵיקֵךָ וגו', מִיָּד (שמות ד, ו): וַיּוֹצִאָהּ וְהִנֵּה יָדוֹ מְצֹרַעַת כַּשָּׁלֶג.
From here Rabbi Judah Halevi bar Rabbi Shalom learned that 11 things cause tzara'at: (1) cursing the Divine name, (2) sexual misconduct, (3) spilling blood, (4) speaking falsely about a fellow person, (5) pride, (6) invading another's place, (7) lying, (8) stealing, (9) swearing falsely, (10) profaning the Heavenly name, and (11) worshiping idols. Rabbi Yitzchak says, "the evil eye" [causes tzara'at]. And our rabbis add, "despising the study of Torah"
[the rabbis give textual proofs of each of those. We are just going to focus on two of those:]
Regarding the opinion of Rabbi Yitzchak who says [tza'arat] is caused by the evil eye, when a person has a stingy nature and does not lend her tools/utensils the Blessed Holy One sends tza'arat to that person's house, and they have to take all the utensils outside, and then people say 'So-and-so, who did not lend her utensils and said she did not have them, look here, she has them!' and about that person the text says: "his house will be revealed by a flood" (Job 20:28)... And an example of someone who "speaks falsely against his fellow person" is Moshe Rabbenu. When God told him to go to save Israel, he said: 'My Master, look, they do not believe in me" as it is said: "And they will not believe me" (Ex. 4:1). G!d said: Moshe! you already know that they don't believe you? They are believers who were brought up by [lit. children of] believers! And you are telling Me they won't believe in you? Now "please put your hand into your shirt." And immediately "when he took it out, his hand was encrusted with snowy scales!" (Ex. 4:6)
So it is that Blessed God does not speak evil about Israel like the father does not speak [evil] about his son; so we find that when a person speaks evil he presents himself as someone who deny that his words are [bound up in] Divine Sovereignty, an Attribute of G!dliness, and therefore he is like one who worships idolatry. And this is the statement of King David, peace be upon him, [May the LORD cut off all flattering lips, the tongue that speaks proud things!] Who have said: “Our tongue will we make mighty” (Psalm 12:5), which is to say that the wicked say “Let us make our tongues mighty to speak because our lips are ours, who is a Lord over us?” Which is to say they deny that G!dliness is in their mouths. But one must have faith that their speech is [bound up in] Divine Sovereignty; and this is the statement of [our Sages] of Blessed Memory, “Who rules over Me? The tzaddik!” (Babylonian Talmud, Moed Katan 16b), which is to say “The tzaddik rules with me, with My speech, which is Divine Sovereignty, ruling over all the Worlds and all the Creations.” And how do we arrive at this faith? It is through engaging in the Torah, meaning when a person speaks words of Torah and connects their speech to the letters of the Torah, through that they bring about Divine Sovereignty. So it is that we find a disagreement in [Babylonian Talmud] Arakhin 15b, “One says that a person who told [evil speech] has no remedy, and one said he should engage in Torah as is stated, the Tree of Life heals the tongue (Proverbs 15:4).” And yet they certainly do not disagree, for this is a principle in all of Torah: “These and these are the words of the Living God” (Babylonian Talmud, Eruvin 14a), so too here when a person engages in Torah not for its own sake [but for some other purpose] they have no remedy, but when they engage [in Torah] for its own sake and connects their speech to the letters of the Torah they thereby brings about Divine Sovereignty; and this is [the meaning of] the Tree of Life heals the tongue.

G!d spoke to Moshe saying "This shall be the Torah of the Metzora (leper): On the day when he is to be purified, he shall be brought to the Cohen." (Vayikra 14:1-2)
Here we are being taught how to serve our Creator. When any evil desire arises to tempt you with regard to any sin, G!d intends you to go perform the mitzvah that is that sin's very opposite. That is why the desire to sin arose within you, like the peel one finds outside a fruit. When one want to eat a nut, they must first break its shell to get at that which lies inside - one cannot get there without going through the shell. Even if one simply refrains from doing the sin, without the shell shattering act of its opposite mitzvah, the desire for the sin will arise again... This is the meaning of our pasuk, "This shall be the teaching of the Metzora" read as "motzi ra" (one who speaks ill). When an opportunity to do evil is at hand, this is what it should teach you: Your intent to breaking through the ra should be the brightness of the mitzva within, thus "on the day he is to be purified [by good speech]". Then the Torah assures us "he shall be brought to the Cohen", being present with G!d in obsevance of a mitzva.
