Tractate Ta’anit, as its name indicates, focuses mainly on the halakhot and themes of fast days, covering both communal fasts and private, individual fasts and addressing both those that have fixed dates and those that are established from time to time in response to various negative events. In the Talmud Yerushalmi and certain works of the early authorities, the tractate is called by the plural term for “fast days”, Ta’aniyot.
There are many references to fasts in Nevi’im (Prophets) and Ketubim (Writings). Numerous verses teach about the meaning and purpose of fast days, as well as the manner of their observance, both communal and individual, as they were practiced by the Jewish people in ancient times. Consequently, the content of Tractate Ta’anit is based on oral traditions transmitted to Moses at Sinai, as expressed in practical terms in many books of the Bible.
As indicated by the Hebrew word ta’anit, a fast is a time of affliction – inui. As explained in the Gemara and in the books of the Nevi’im and Ketubim, on a fast day one abstains from eating and drinking. For the most important fasts, the Sages added the prohibitions against wearing shoes, engaging in conjugal relations, anointing and bathing. Nevertheless, both the prophets and the Sages stress that the fasting and other suffering that one accepts upon himself are not the purpose and ultimate aim of the fast day. See, for example, Yeshayahu, chapter 57, which is read on Yom Kippur. The fasting and other suffering are merely a means of achieving atonement and purity of the soul. It is prayer, charity, and repentance, i.e., a reconsideration of past actions and an acceptance of improvement for the future, which constitute the main focus of fast days. For this reason Tractate Ta’anit does not focus on the detailed halakhot of fasting, but on the other aspects of the day: The additional prayers and spiritual awakening through study and action.
The most common misfortune that should stir feelings of repentance is a lack of rain, and therefore most of the tractate deals with this issue. As stated in the Torah ( 11:17), a drought is a sign of God’s anger, as both a warning and a punishment. At a time of a dearth of rain, even more than with other disasters, one has no way to improve the situation other than by turning to God and praying. Furthermore, a lack of rain is not simply a local or temporary problem; it can bring catastrophe on the entire country. Much of Tractate Ta’anit, and indeed many of the halakhot of fast days, concern fasts established to entreat God for rainfall.
Any communal fast that does not have a fixed date, i.e., which is neither a response to a current emergency nor commemorates a historical event, is established on a Monday or Thursday, the days on which the Torah is read in public and the courts would convene.
Naturally, there is a gloomy, even mournful, aspect to fasts, as they are declared for sad events and are intended to prevent misfortunes from continuing or becoming worse. One exception to this rule is Yom Kippur, which is classified as a Festival, and which includes the joy of purification.
Sometimes a person will accept a fast upon himself, generally by means of a declaration during the afternoon service of the previous day, as part of a broader effort to achieve atonement for his sins, or as a request that he will not suffer a certain misfortune, e.g., one that appeared in his dreams. Naturally the status of a fast of an individual, or even a collection of individuals, is unlike that of a communal fast, with regard to both its severity and to the manner of its initiation. In the case of a community these are determined by the events of the day and the needs of the public.
In addition, there are also fixed fast days of memorial which were established to commemorate disasters and occurrences of earlier generations. These days are not only days of fasting and memorial, but also days of mourning. Virtually all the mitzvot and prohibitions that apply to someone in mourning for the dead are obligatory for everyone on the Ninth of Av. With the exception of Yom Kippur, all fast days apply by rabbinic law.