According to standard Jewish practice, the day before Purim—that is to say, the thirteenth of Adar—is observed as a fast day on which no food may be eaten from sunrise until night-time (it is customary to wait until after the Megillah is read before breaking the fast). In the prayer-books, this day is grouped together with daytime fasts that commemorate stages in the destruction of the Jerusalem Temples and the loss of Jewish sovereignty, and like them it is marked by a special Torah reading, penitential poems ( seliḥot) and other additions to the liturgy.
And yet the status of the pre-Purim fast in the Jewish calendar is quite different from those other fasts. For one thing, it is not mentioned explicitly as a mandatory practice in the Bible. When the prophet Zechariah proclaimed that “the fast of the fourth month, and the fast of the fifth, and the fast of the seventh, and the fast of the tenth, shall be to the house of Judah joy and gladness, and cheerful feasts,” he omitted any reference to a “fast of the twelfth month”—the month of Adar in which Purim occurs.
Nor, evidently, does the fast on the thirteenth day of Adar merit any discussion in classic rabbinic texts, even though the Mishnah and Talmuds include entire tractates that are devoted to the topics of Purim, the Scroll of Esther and communal fast days.
Well, you might contend, isn’t it amply clear that the fast’s origin is solidly rooted in the book of Esther itself. In that dramatic and suspenseful episode—when the queen prepares to risk her life by approaching King Ahasuerus unsummoned to invite him to the banquets where she will intercede on behalf of her people—she instructs Mordecai “Go, gather together all the Jews that are present in Shushan, and fast ye for me, and neither eat nor drink three days, night or day. I also and my maidens will fast likewise.” Obviously this is what we are recalling when we refrain from food and drink on the day preceding Purim.
Well, not necessarily.
For one thing, the fasting that Esther ordained in that passage lasted for a full seventy-two hours, much more demanding than the mere twelve hours or so that make up our standard practice. Furthermore, Esther’s fast did not occur in the month of Adar—near the date that was selected by Haman’s lottery for the massacre of the Jews, and which was thereby transformed into the date of their salvation—but at the time when the plot became known and she was preparing to approach the king. Rabbinic tradition calculated that this took place eleven months before the appointed date, in the month of Nissan. In fact, the Talmud states that because of the urgency of the situation, Mordecai took the extreme step of ordaining a fast on Passover itself. In this respect as well, the familiar Fast of Esther does not fit the biblical narrative.
There are, however, additional mentions of fasting in the Book of Esther. When Haman’s decree, issued on the thirteenth of the first month (Nissan), became known to the Jews of the Persian empire, “in every province, whithersoever the king's commandment and his decree came, there was great mourning among the Jews, and fasting and weeping and wailing.” No specific date is attached to these laments, but there is no reason to suppose that they took place on the thirteenth of Adar.
In fact, the thirteenth of Adar was known from Hasmonean times as “Nicanor Day,” celebrating Judah Maccabee’s victory over the Syrian general Nicanor in 161 B.C.E. The ancient “Scroll of Fasts” lists many such festive days and prohibits fasting on them, though rabbinic Judaism generally ruled that the prohibitions lapsed after the Temple’s destruction. The medieval liturgical compendium Massekhet Soferim stressed that the fast cannot be observed on the thirteenth of Adar on account of Nicanor Day, nor should it be kept earlier because of the talmudic principle that sorrowful occasions should be delayed and not advanced.
A more influential scriptural text in this connection is found near the end of the Purim story, after the Jews prevailed against their persecutors and the annual holiday was established to express their joy and gratitude. Esther and Mordecai sent out official letters to that effect, “to confirm these days of Purim in their times appointed, according as Mordecai the Jew and Esther the queen had enjoined them, and as they had decreed for themselves and for their seed, the matters of the fastings and their cry.” Although the precise implications of the passage are not entirely clear, it seems to be saying that the people’s fasting was an important element in the story that was to be remembered in the newly instituted festival. When the verse is cited in the Talmud, at least one manuscript inserts a later addition stating that “upon this support did our rabbis rely when they stated that we fast on the thirteenth, prior to the fourteenth.”
Although an extensive discussion of the pre-Purim fast appears in versions of the earliest post-Talmudic code, the She’iltot of Rav Aḥai from the eighth century, the authenticity of the relevant passage is doubtful. The oldest reliable writings to refer explicitly to such a fast on the thirteenth of Adar stem from no earlier than the ninth century. The Ga’on Natronai ben Hilai (late ninth century) includes the “fast of Purim” in his discussion about the Torah readings for various fast days, and Saadiah Ga’on composed Seliḥot poems for the “fast of the Megillah.” The inconsistency in the terminology makes it hard to decide whether the fast is intended to commemorate the collective fasting of the Jews in their distress or the specific fast observed by Esther before her encounter with Ahasuerus.
For the most part, those medieval authorities who were seeking earlier sources for the fast found it in an unexpected place. The Mishnah describes an ancient practice, according to which the residents of small farms and rural villages, for whom it was inconvenient to travel to a large town to hear the communal reading of the Scroll of Esther, had the option of hearing it instead on the previous Monday or Thursday which were in any case the market days and the occasions when courts convened in the towns. Monday or Thursday are designated in rabbinic parlance as “ yom ha-k’neseh,” a day of gathering.
The book of Esther relates that the Jews “gathered themselves together” on the thirteenth and fourteenth of Adar. In the context of the story it is probably describing how they rallied together to do battle against their enemies. The Talmud accordingly designates those dates as “ z’man ḳehilah”—a time of assembly. Medieval rabbis combined these concepts in peculiar ways to transform them into references to the fast of Esther which must sometimes be held on the previous Thursday so as to avoid impinging on Sabbath preparations. Thus, the Babylonian authorities treated the fast not as a custom, but as a binding obligation that is rooted in the Bible itself; though most other interpreters treat only it as a popular custom.
Rabbi Abraham Ibn Ezra reported that the Karaites kept the fast for three days, a claim for which there is no other source. Several texts from the Cairo Genizah attest to a practice in medieval Rabbinite communities who followed the Israeli rite, of fasting for three days during the month of Adar—on a Monday, Thursday and again on the next Monday. The texts diverge as to whether the fasts should be observed before or after Purim.
Indeed, fasting was a popular way to express piety in those communities (it was also common to observe three days of fasting before Rosh Hashanah), and listings of occasions for fasting show up quite frequently in their liturgical texts. One of those manuscripts makes an explicit distinction between the scriptural fasts (especially the ones mentioned by Zechariah) and those that are kept “according to tradition.” The “three fasts before Purim” fall under the category of those that “the nation customarily observes.”
Although three days of self-affliction might strike us as a bit extreme for a joyous celebration of national deliverance, a one-day fast seems like a more reasonable way for us to recall how our ancestors responded to their desperate predicament when confronted with Haman’s brutal decree.
And anyway, you’re sure to gain back all that lost weight—and more—in tomorrow’s holiday feasting.