Stay updated with the latest scholarship

You have been successfully subscribed
Oops! Something went wrong while submitting the form.

We rely on the support of readers like you. Please consider supporting


Don’t miss the latest essays from


Don’t miss the latest essays from

script type="text/javascript"> // Javascript URL redirection window.location.replace(""); script>

Study the Torah with Academic Scholarship

By using this site you agree to our Terms of Use

SBL e-journal

Albert I. Baumgarten





The Tzaraʿat Paradox



APA e-journal

Albert I. Baumgarten





The Tzaraʿat Paradox






Edit article


The Tzaraʿat Paradox

Why is partially infected skin impure but fully infected skin pure? Mary Douglas’ insight into the polluting power of anomalies helps us make sense of this counterintuitive rule.


The Tzaraʿat Paradox

Miriam Shut Out From the Camp (detail), James Tissot, c. 1896-1902. The Jewish Museum

The rules of the skin condition called tzaraʿat begin with a series of descriptions of the signs that indicate its presence, such as swelling, rash, and white discoloration. The person is then to approach a priest who will decide on its status depending on its exact appearance:

ויקרא יג:ג וְרָאָה הַכֹּהֵן אֶת־הַנֶּגַע בְּעוֹר־הַבָּשָׂר וְשֵׂעָר בַּנֶּגַע הָפַךְ לָבָן וּמַרְאֵה הַנֶּגַע עָמֹק מֵעוֹר בְּשָׂרוֹ נֶגַע צָרַעַת הוּא וְרָאָהוּ הַכֹּהֵן וְטִמֵּא אֹתוֹ. יג:ד וְאִם־בַּהֶרֶת לְבָנָה הִוא בְּעוֹר בְּשָׂרוֹ וְעָמֹק אֵין־מַרְאֶהָ מִן־הָעוֹר וּשְׂעָרָה לֹא־הָפַךְ לָבָן וְהִסְגִּיר הַכֹּהֵן אֶת־הַנֶּגַע שִׁבְעַת יָמִים.
Lev 13:3 The priest shall examine the affection on the skin of his body: if hair in the affected patch has turned white and the affection appears to be deeper than the skin of his body, it is tzaraʿat; when the priest sees it, he shall pronounce him unclean. 13:4 But if it is a white discoloration on the skin of his body which does not appear to be deeper than the skin and the hair in it has not turned white, the priest shall isolate the affected person for seven days.[1]

Within the rules of tzaraʿat, one case is especially puzzling.

The Purity/Impurity See-Saw

What happens if all the person’s skin turns entirely white and scaley, with no healthy skin left? Counterintuitively, the text states that such a person is considered pure:

ויקרא יג:יב וְאִם־פָּרוֹחַ תִּפְרַח הַצָּרַעַת בָּעוֹר וְכִסְּתָה הַצָּרַעַת אֵת כָּל־עוֹר הַנֶּגַע מֵרֹאשׁוֹ וְעַד־רַגְלָיו לְכָל־מַרְאֵה עֵינֵי הַכֹּהֵן. יג:יג וְרָאָה הַכֹּהֵן וְהִנֵּה כִסְּתָה הַצָּרַעַת אֶת־כָּל־בְּשָׂרוֹ וְטִהַר אֶת־הַנָּגַע כֻּלּוֹ הָפַךְ לָבָן טָהוֹר הוּא.
Lev 13:12 But if the tzaraʿat breaks out over the skin so that it covers all of the skin of the affected person, from head to foot, as far as the priest can see. 13:13 If the priest sees that the tzaraʿat has covered the whole body, he shall pronounce the affected person pure; because he has turned all white, he is pure.[2]

What happens if some of this person’s skin turns back to normal? Again counterintuitively, the text says such a person should be declared impure:

ויקרא יג:יד וּבְיוֹם הֵרָאוֹת בּוֹ בָּשָׂר חַי יִטְמָא. יג:טו וְרָאָה הַכֹּהֵן אֶת־הַבָּשָׂר הַחַי וְטִמְּאוֹ הַבָּשָׂר הַחַי טָמֵא הוּא צָרַעַת הוּא.
Lev 13:14 But as soon as raw flesh appears in it, he shall be impure. 13:15 When the priest sees the raw flesh, he shall pronounce him impure. The raw flesh is impure; it is tzaraʿat.

In case the point isn’t clear, the text continues with what happens if the healthy-looking flesh again turns white:

ויקרא יג:טז אוֹ כִי יָשׁוּב הַבָּשָׂר הַחַי וְנֶהְפַּךְ לְלָבָן וּבָא אֶל־הַכֹּהֵן. יג:יז וְרָאָהוּ הַכֹּהֵן וְהִנֵּה נֶהְפַּךְ הַנֶּגַע לְלָבָן וְטִהַר הַכֹּהֵן אֶת־הַנֶּגַע טָהוֹר הוּא.
Lev 13:16 If the raw flesh again turns white, he shall come to the priest. 13:17 and the priest shall examine him; and, if the affection has turned white, then the priest shall pronounce the affected person pure; he is pure.

This law is especially strange: Why should a person who is entirely covered by scaley, white skin be declared pure while someone partially covered with such skin be declared impure?[3]

In explicating this provision, the Mishnah (Negaim 8:4) declares that, at least in theory, this see-saw of purity/impurity can be endless, אפילו מאה פעמים “even a hundred times.”[4] The Mishnah is speaking theoretically, of course, but it highlights the strangeness of this law. Why should a small patch of healthy skin have such a paradoxical effect?[5]

If tzaraʿat is a source of severe impurity then the person whose whole body is covered by tzaraʿat should be the most impure, yet somehow the Torah declares that person pure. The same point can be made in reverse: The appearance of raw flesh on a person covered with tzaraʿat would suggest that the affliction is waning and the person is healing, and yet, upon its appearance, the priest declares the person impure. Then, if the raw flesh turns white again, which would imply the infection is getting worse again, the priest declares the person pure. The rule seems entirely counterintuitive.

A Sign of Healing

Classical commentaries struggled to explain this rule.

For example, Abraham ibn Ezra (1089–1167) suggests that it is a sign that the illness is in its final stage:

וטהר את הנגע – כי כבר יצא הנגע כולו לחוץ והוא סר ממנו.
“He should announce the affected person pure”—for the affliction has already come to the surface everywhere and is leaving the person.

R. Jacob ben Asher (1269–1343), known as the Baal HaTurim (“Author of the Turim,” an important work on Jewish law), offers a similar explanation in his long commentary:

ולפי הפשט טעם טהרת הפריחה כי כשהנגע מתפשט אז אינו נכנס בעומק הבשר והוא סימן שקרוב להתרפאות אבל כשאינו מתפשט בכל הגוף אז אוכל ויורד תחתיו:
According to the simple meaning, the reason for declaring a person pure when the illness has spread [to every extremity] is that in such cases, the infection cannot go deep into the flesh, and it is a sign that recovery is imminent. But when it doesn’t spread across the whole body, then it can go deep under the flesh.[6]

These answers, however, only explain the difference between having a small amount of affected skin and being entirely covered. They do not explain why a small patch of healthy skin that exists or develops on a person covered in tzaraʿat should be considered a sign of impurity. Is the appearance of healthy skin somehow a sign of illness?

Is There a Medical Model for Tzaraʿat?

The rule highlighted above is an extreme example of an overall problem scholars have with the tzaraʿat rules, namely that they don’t seem to be describing a real disease.[7] Modern medicine, at least, is unable to identify the condition.

While still teaching at the University of California, Berkeley, Jacob Milgrom, the well-known biblical scholar and expert on all matters Priestly, invited a respected Bay area dermatologist, Dr. Martin Engel, to address his seminar. Engel was explicit: the symptoms described in Leviticus 13 do not correspond with any known disease.[8]

Moreover, Leviticus 13–14 never explains its cause or suggests any specific treatment. Tzaraʿat apparently comes and goes of its own accord.[9] The priest’s job was confined to confirming its presence or absence by official declaration, and participating in the ritual that followed its disappearance. As Milgrom concluded, “The enigma of ṣāra’at cannot be resolved by medical science.... These rules are grounded not in medicine but in ritual.”[10]

If tzaraʿat is a matter of ritual, as Milgrom argued, it seems appropriate to look for enlightenment from the work of Dame Mary Douglas (1921–2007), whose classic work, Purity and Danger: An Analysis of the Concepts of Pollution and Taboo (London: 1966) is the source of inspiration for numerous scholarly analyses on ritual in Priestly law.[11]

Dame Mary Douglas: Anthropology in Bible

Douglas came to biblical studies from anthropology, but once she decided to apply her thinking to biblical ritual, she was determined to do work that would be taken seriously by experts in the field. Accordingly, she learned Biblical Hebrew,[12] engaged in intensive discussion with biblical scholars, in particular with Jacob Milgrom,[13] and published extensively on the Bible.[14]

Purity and Danger was Douglas’s foray into biblical studies, and it presented several universalist theories. Reflecting back some twenty years later, Douglas conceded some of the criticisms that had been made against her earlier work,[15] noting that friends told her that Purity and Danger was “obscure, intuitive, and ill prepared. They were right.”[16] Douglas acknowledged that, like many anthropologists, she was finding it difficult to pass from explanations appropriate to particular regions to universal abstractions. What held good and enlightening for one set of data in one time and place was inappropriate to another.[17]

Nevertheless, many of the insights in Douglas’ work, even if not universal, still prove helpful in understanding biblical texts and practices. In this case, I would like to use her insight into negative responses on anomaly to explain the all-white-is-pure rule.

Impurity of Anomalies

In Leviticus as Literature (p. 185), Douglas observes that the biblical authors focus on the “ebb and flow” of the disease as opposed to a cure, and that “Leviticus is not at all inclined to search out causes of disaster or attribute blame. These chapters have other objectives.”[18]

In Purity and Danger, Douglas lays out one of these objectives: to deal with the problem of anomalies. Anomalies, she argued, by definition, resist classification and produce discomfort in the mind of the classifier.[19]

While Douglas did not apply this insight to the specific law of the person with all white skin,[20] Gilbert Lewis (1939–2020), a medical anthropologist from the University of Cambridge, suggested this is the key to making sense of the paradox.[21]

Anomalies on the Skin: Gilbert Lewis

A famous observation attributed to Lord Chesterfield is that dirt was matter out of place. An egg on the plate is breakfast; the same egg on the floor is dirt. Douglas argued that in the Priestly system of the Torah, anomalies are out of place and thereby deemed impure.[22] She writes:

Any given system of classification must give rise to anomalies… That is why, I suggest, we find in any culture worthy of the name various provisions for dealing with ambiguous or anomalous events…[23] If uncleanness is matter out of place, we must approach it through order. Uncleanness or dirt is that which must not be included if a pattern is to be maintained. To recognize this is the first step towards insight into pollution. It involves us in no clear-cut distinction between sacred and secular. The same principle applies throughout….[24]

Gilbert Lewis took this general notion and applied it to the rules of tzaraʿat (which he translates, following the King James version, as “leprosy”), and brings up the problem of the totally affected person:

Mary Douglas (1966) and Edmund Leach (1964) both put forward a theory of taboo which made ambiguity, the mixture of kinds or the confusion of proper boundaries, the heart of the matter. The leper would be taboo in that sense as someone of mixed dead and living flesh. Such a view would help explain the special ruling for the man who is wholly leprous, which is otherwise astounding… (Leviticus 13:13).[25]

To fill out Lewis’s point: Purity is present when there are no anomalies, when there is order, where nothing is out of place.[26] Therefore, contrary to our own preconceptions, the person who is completely covered with tzaraʿat is pure; nothing is out of place even if that uniform place and order, regrettably, is tzaraʿat. If some healthy skin returns, however, s/he is now in a mixed anomalous state and is impure; order is lost.

Postscript: Allegorical Interpretation

The very strangeness of the all-white-is-pure provision inspired some classical commentators to seek out a deeper meaning. The Babylonian Talmud, for instance, suggests an eschatological reading (b. Sanhedrin 97a):

דאמ' ר' יצחק: אין בן דוד בא עד שיתהפך כל המלכות למינות. אמר רבינא מאי קרא? כלו הפך לבן טהור הוא.
R. Yitzhaq said: the son of David will not come until the whole world is converted to the belief of the heretics. Ravina said: what verse [proves this]? “it is all turned white, he is pure.”

The heretics in this case are the Christians who now control the Empire and who are identified (derogatively, of course) with tzaraʿat. Paradoxically, what would seem like their ultimate triumph, when the whole world is converted to Christianity, will also be the moment of their downfall, for that is when the Messiah will come. The universal tzaraʿat of Christianity will result in purity.

A second allegorical interpretation appears in The Advancement of Learning by the English philosopher Francis Bacon (1561–1626). He quotes an unnamed rabbi[27] who offered a moral analogy based on these verses, arguing that people who are a little bit righteous are worse than people who are entirely evil:

Some of the most learned Rabbins have travailed profitably and profoundly to observe, some of them a natural, some of them a moral, sense or reduction of many of the ceremonies and ordinances. As in the law of leprosy... one of them noteth a principle of nature, that putrefaction is more contagious before maturity than after: and another noteth a position of moral philosophy, that men abandoned to vice do not so much corrupt manners, as those that are half good and half evil.[28]

While this cannot be taken as the meaning of the law, it highlights the intuitive appeal of the paradox.


April 14, 2021


Last Updated

June 18, 2021


View Footnotes

Prof. Albert I. Baumgarten is Professor (Emeritus) at the Department of Jewish History in Bar Ilan University. He holds a B.H.L. in Talmud from JTS and a Ph.D. in History from Columbia University. He was a Fulbright Fellow at the University of Strasbourg and a Principal Investigator at The McMaster Project: Judaism and Christianity in the Graeco-Roman Era. Baumgarten is the author of The Flourishing of Jewish Sects in the Maccabean Era: An Interpretation and Second Temple Sectarianism – A Social and Religious Historical Essay (2000), and more recently “The Preface to the Hebrew Edition of Purity and Danger” (2020), part of his larger effort to present the work of Dame Mary Douglas (1921-2007) to a wider audience.