Why Does Tzara’at Occur? The Causes of Nega’im in Chazal

The Torah’s treatment of tzara’at is unlike the treatment of an ordinary physical condition. A visible nega may appear on a person’s skin, clothing, or home, yet its Torah status is determined specifically by a Kohen. Chazal and the classical commentaries describe these afflictions as carrying a message—one that calls upon the affected person to examine his conduct and return to the proper path.

This discussion concerns tzara’at as defined by the Torah and Chazal. It should not be equated automatically with psoriasis, Hansen’s disease, or any other modern dermatological diagnosis.

Why Is the Nega Brought to a Kohen?

The Torah states:

וְהוּבָא אֶל אַהֲרֹן הַכֹּהֵן אוֹ אֶל אַחַד מִבָּנָיו הַכֹּהֲנִים
“He shall be brought to Aharon the Kohen, or to one of his sons, the Kohanim.”

— Vayikra 13:2

The determination of tumah or taharah in nega’im belongs to the Kohen. Sforno explains that the Kohen instructs the affected person to examine his deeds and pray, while the Kohen himself also prays for him. Through their continuing involvement with nega’im, the Kohanim develop טביעות עין—a trained eye capable of distinguishing between the different appearances.

The Zohar gives the Kohen’s perception an additional dimension. In discussing נגע צרעת כי תהיה באדם והובא אל הכהן, it describes the Kohen as knowing how to distinguish the character of the affliction—whether it represented יסורין דרחימותא, afflictions of love, or an affliction connected with a person’s conduct. The Zohar concludes:

דהא לפום ארחוי דבר נש גרים נגע בעלמא
“For according to a person’s ways, he causes the nega in the world.”

— Zohar, Tazria, vol. III, 47a

The picture that emerges is therefore not merely of someone inspecting a physical mark. The Kohen stands at the intersection of the Torah’s detailed laws of nega’im and the process of reflection and correction that the nega is intended to awaken.

Transgressions Associated With Tzara’at

Across Chazal and the classical commentaries, a number of causes are associated with nega’im. Among them are:

The Seven Causes Listed in the Talmud

The Gemara in Arachin 16a records Rabbi Yochanan’s teaching that nega’im come because of seven things:

1. לשון הרע — Lashon hara
2. שפיכות דמים — Bloodshed
3. שבועת שוא — A false or vain oath
4. גילוי עריות — Forbidden sexual relations
5. גסות הרוח — Haughtiness
6. גזל — Theft
7. צרות העין — Stinginess

The Gemara does not merely provide a list; it brings Scriptural indications for each category. Miriam and the broader teachings concerning harmful speech form the classic association between tzara’at and lashon hara, while other Biblical episodes connect nega’im with bloodshed, false oaths, forbidden relations, arrogance, theft, and refusal to share one’s possessions.

The Eleven Causes in Midrash Tanchuma

Midrash Tanchuma, Metzora 4 gives an even broader list. It asks:

על כמה דברים נגעים באים על האדם?
“For how many things do nega’im come upon a person?”

The Midrash answers that nega’im come for eleven matters:

1. עבודה זרה — idolatry
2. חילול השם — desecration of God’s Name
3. גילוי עריות — forbidden sexual relations
4. גניבות — theft
5. לשון הרע — lashon hara
6. מעיד עדות שקר — giving false testimony
7. דיין המקלקל את הדין — a judge who corrupts justice
8. שבועת שוא — a vain oath
9. נכנס בתחום שאינו שלו — entering a domain that is not his
10. חושב מחשבות של שקר — harboring thoughts of falsehood
11. משלח מדנים בין אחים — sowing discord between brothers

The Midrash adds another opinion: ויש אומרים אף על עין רעה—some say that nega’im also come because of an ayin ra’ah, understood here as stinginess or unwillingness to share with others.

Can the Appearance of the Nega Point to Its Cause?

This is where several classical commentaries add an important dimension. The different descriptions in Parashat Tazria are not necessarily treated as interchangeable manifestations.

The Siftei Kohen commentary to the Torah develops correspondences between the Torah’s different descriptions of nega’im and the transgressions associated with them. Among the correspondences he identifies are:

Other commentators similarly read meaning into the specific terminology of the nega. The Kli Yakar, for example, associates שאת—literally something raised—with arrogance; ספחת, something attached or secondary, with an unhealthy attachment to material possessions; and the whiteness of בהרת with lashon hara, which can cause another person’s face to turn white from humiliation.

These interpretations make the Torah’s extraordinary level of visual detail significant on more than one level. The Kohen must know the technical laws governing the appearance, size, spread, hair, color, and location of a nega. At the same time, the classical sources teach that nega’im belong to a moral and spiritual system in which the outward manifestation can reflect an inward problem.

When Remaining Silent Becomes Part of the Problem

One of the less commonly discussed causes appears in the Zohar. It teaches that just as a person may be punished for harmful speech, there are circumstances in which he may also be held accountable for failing to speak when constructive speech is required.

The Zohar describes a situation in which people are proceeding on a corrupt path and someone who has the ability and responsibility to admonish them remains silent:

כל שכן אי עמא אזלין בארחא עקימא והוא יכיל למללא להו ולאוכחא להו ושתיק ולא מליל

— Zohar, Tazria, vol. III, 46b

Tzara’at therefore cannot be reduced simply to “the punishment for lashon hara.” Speech is certainly central, but the sources describe a much wider moral landscape: what a person says, what he refuses to say, how he handles money, how he treats other people, whether he creates harmony or division, whether he respects boundaries, and how he relates to positions and responsibilities established by the Torah.

Tzara’at and the Kehuna

The connection with the Kehuna itself is especially significant. Following the rebellion of Korach, the Torah warns against a non-Kohen approaching to perform the service assigned to the descendants of Aharon. Chazal understand the unusual wording כאשר דבר ה’ ביד משה לו as containing an allusion to tzara’at—the affliction that appeared on Moshe’s hand—and associate improper challenge to the Kehuna with this punishment.

This gives additional meaning to the fact that the Torah places the determination of nega’im specifically in the hands of a Kohen. The person must come before a representative of the very institution whose defining ideals include service, restraint, peace, and fidelity to the distinctions established by the Torah.

Sources

1. Zohar, Tazria, III 46b–47a. On harmful speech, failure to speak when rebuke is required, and the Kohen’s perception of the character of a nega.
2. Arachin 16a. Seven causes of nega’im: לשון הרע, שפיכות דמים, שבועת שוא, גילוי עריות, גסות הרוח, גזל, צרות העין.
3. Midrash Tanchuma, Metzora 4. The eleven causes of nega’im, with an additional opinion concerning עין רעה.
4. Midrash Tanchuma, Tazria 11. Tzara’at associated with זנות; see also Mishlei 6:32–33 and Baal HaTurim to Kohelet 8:9 as cited in the original source notes.
5. Kli Yakar, Bamidbar 5:2. The צרוע associated with avodah zarah and the language used following the sin of the Golden Calf.
6. Chizkuni, Bamidbar 5:6. נסמכה פרשת מעילה לפרשת זב ומצורע—the juxtaposition teaches that zivah and tzara’at may come through מעל וחטא.
7. Sanhedrin 110a; Bamidbar 17:5; Kli Yakar ad loc. The connection between improper challenge to the Kehuna and tzara’at.
8. Sforno, Vayikra 13:5 and 14:57. The Kohen’s role in directing the afflicted person to examine his deeds and the expertise required to distinguish among nega’im.
9. Siftei Kohen al HaTorah, Parashat Tazria–Metzora. Correspondences between specific categories and descriptions of nega’im and particular transgressions.
10. Kli Yakar, Vayikra 13:2. The symbolic relationship of שאת, ספחת ובהרת to arrogance, attachment to wealth, and lashon hara.