“Since it has been postponed, let it be postponed altogether.”[1] Such was the opinion of Rabbi Judah HaNassi[2] regarding a time when the fast day of Tish’ah B’Av (the 9th of Av) fell on Shabbat.

There are four fast days in the Jewish calendar that were instituted by the prophets and sages to commemorate the destruction of the two Holy Temples in Jerusalem:

a) The 10th of Tevet, on which Nebuchadnezzar’s armies laid siege to Jerusalem, in the time of the First Temple.

b) The 17th of Tammuz, the day on which the Temple service was disrupted in the time of the First Temple, and on which the walls of Jerusalem were breached by the Romans in the time of the Second Temple.[3]

c) The 9th of Av, on which both Temples were destroyed; the First Temple by the Babylonians in the year 3338 from creation (423 bce) and the Second Temple by the Romans in 3829 (69 ce).[4]

d) The 3rd of Tishrei, which commemorates the assassination of Gedaliah ben Achikam, the governor of Judea. The murder of Gedaliah spelled the end of the small Jewish community that remained in the Holy Land after the destruction of the First Temple.

On these days we deprive our body of food and drink, stirring ourselves to repent the sins and shortcomings that twice caused the destruction of G-d’s home and our banishment into galut (exile). The strictest of these fast days is the 9th of Av, on which the fast begins at sunset of the previous evening (whereas the other three fasts begin at dawn of that day), and on which additional physical pleasures are also forbidden.[5]

On Shabbat, however, it is a mitzvah to pleasure ourselves with food and drink—a mitzvah which supersedes the injunction to fast. So when a fast day falls on Shabbat, the fast is postponed to the following day, while on Shabbat itself—even if it is the 9th of Av—“One should eat meat and drink wine... and set his table even like the feast of Solomon[6] during his kingship.”[7]

In this context, the Talmud cites Rabbi Judah HaNassi’s opinion that “Since it has been postponed, let it be postponed altogether.” According to Rabbi Judah, when the 9th of Av falls on Shabbat, the fast ought to be canceled completely.

The prophet Isaiah describes a fast day as “a day of goodwill before G-d.”[8] In other words, the negative aspects of the fast day—the mourning, the recollection of our failings, the deprivation of the body—are not what define its essence. At its core, the fast day is a wholly positive phenomenon: a day of opportunity for man to bring himself closer to his Creator.

Why then the need to deny ourselves food and drink on such a day? Only because the material aspects of life tend to erect barriers between ourselves and G-d. We must therefore lessen our involvement with the material—to the extent of forswearing some of our body’s most basic needs—thereby freeing our soul to take advantage of the “day of goodwill before G-d” without hindrance and obstruction from our physical selves.

This explains why in the era of Moshiach the fast days will be “transformed into days of gladness and joy... festival days.”[9] In the perfect world of Moshiach, the physical creation will no longer obscure the face of its Creator; on the contrary, it will equal, and even surpass, the spiritual as an expression of the all-pervasiveness of the divine truth.[10] So there will be no need to suppress the physical self in order to actualize the positive essence of the fast days. Rather, these will be festivals, on which the body’s joy and pleasure will contribute to the deepening of the bond between G-d and man.

Shabbat is a weekly taste of the world “that is wholly Shabbat and tranquillity, for life eternal.”[11] Thus, when a fast day falls on Shabbat, there occurs a similar process to that which will transpire in the time of Moshiach when the fast days will be stripped of their negative husk and their wholly positive core will be exposed.

In other words, a fast day occurring on Shabbat is not a clash between two opposing elements in which the stronger element (Shabbat) overpowers the weaker (the fast day), relegating it off to another time. Rather, the essence of Shabbat and the essence of the fast day are fully compatible; Shabbat only repels certain external aspects of the fast day. So it’s not that the fast day is not being observed on Shabbat: it is being observed in a different manner—a manner that is more consistent with its true function. It is being observed in the manner in which it will be observed in the perfect world of Moshiach.

This explains Rabbi Judah’s view that when the 9th of Av falls on Shabbat, the fast day should be “postponed altogether.” For on such a year, Shabbat has enabled us to actualize the quintessential function of the fast day as a “day of goodwill before G-d” without the negative externalities it requires on other days. There is no further need, maintains Rabbi Judah, for a day of fasting.

In actual practice, we do not follow Rabbi Judah’s view. When the 9th of Av falls on Shabbat, we observe the day in its joyous, messianic form on that day; but on the next day, we observe it again, this time with the negative trappings that accompany a fast day in our still unperfected world.

For Shabbat is only a “taste” of a future perfection. We still inhabit a world in which our material involvements tend to obscure, rather than enhance, our spiritual sensitivities; in which the needs of physical life tend to interfere with, rather than facilitate, our relationship with G-d. Even on Shabbat, we experience only a semblance of the absolute harmony between Creator and creation that Moshiach will bring. So after sampling a messianic Tish’ah B’Av on Shabbat, we must observe another, “ordinary” Tish’ah B’Av on Sunday in order to fully exploit the day of goodwill granted us by G-d.

Nevertheless, Shabbat leaves its mark: the laws of a “postponed” Sunday fast are more lenient than an unpostponed Tish’ah B’Av.[12] And ever present in our awareness is the vision of Rabbi Judah HaNassi—a vision even more pertinent today as we stand on the threshold of the era of Moshiach and the elimination of all negative elements that still cling to the periphery of our lives.

Based on the Rebbe’s talks on Shabbat, Tammuz 17, and Shabbat, Av 9, 5751 (1991) and on numerous other occasions[13]