Article: Do I have to fast?
The most stringent of all fast days is Yom Kippur, since fasting is min haTorah (a Biblical law), as the passuk in Parashas Acharei Mos says: “Ta’anu es nafshoseichem” (afflict your souls)—and the severe punishment for not fasting is kareis (early death by Divine decree). Only a heter (dispensation) dispensed by a rav in critical circumstances and in a strictly prescribed manner would allow breaking the fast. A choleh she’ein bo sakanah (a person who has a non-life threatening illness) and similarly, a woman who is expecting or nursing (under normal circumstances), must fast.
Four other fasts are rooted in divrei kabbalah (the words of receiving, i.e. from the Prophets): Tzom Gedaliah, Asara B’Teves, Shiva’a Asar B’Tammuz and Tisha B’Av, and they are subject to stricter rules than for other laws mi’d’rabbanan (of Rabbinic origin). (Taanis Esther is in a different category of minhag—custom.)
Tisha B’Av, due to its history of huchpalu bo tzaros (double tragedies), is more stringently observed: We begin fasting at sunset the evening before and observe the additional bodily afflictions as on Yom Kippur. But the other three fasts of divrei kabbalah are more minor; they were instituted for calamities associated with the churban (destruction [of the Temple]) and during times of relative peace afterwards were commemorated only as a standing tradition previously accepted by Klal Yisroel (the Jewish people).
One of the leniencies of these three fasts is that an expectant or nursing mother who is mitzta’eres harbeh (in much physical discomfort) does not have to fast. Poskim state that lav davka (not necessarily) must the discomfort be acute—even some difficulty suffices as a heter. By contrast, a choleh she’ein bo sakanah, and similarly, an expectant or nursing mother who is suffering undue weakness or one who is at a stage of her pregnancy where fasting is deemed unhealthy for her (or for the fetus) and would therefore be considered a choleh—is patur (exempt) from fasting on all four fast days, including Tisha B’Av.
A mother of small children who is not expecting or nursing is not included in this heter, and neither is one who is paid to care for others’ children, as there is hardly a career or calling that exempts an individual from the halachic obligation to fast. One halachic opinion states that women should not have to fast for twenty four months after giving birth (the official halachic time span for nursing) and another exempts all those of childbearing age, but these views are rejected by mainstream poskim.
There is some extra leniency regarding Tzom Gedaliah (compared to the other two fasts of divrei kabbalah) for those who are not otherwise exempt, but would not be physically able to fast on Yom Kippur only one week after fasting on Tzom Gedaliah. In such a case, a rav should be consulted.
From Halacha2Go Archives