Fasting has always been a part of the profound process of soul purification for Jews. Purity of thought and action were considered the key to happiness in both this world and the next. According to Jewish belief, God keeps a strict accounting of each person’s deeds, and in accordance with this record, He metes out justice. If one wishes to ward off divine punishment, he must repent of his sins and cleanse himself of them. When he repents, he first recognizes his transgressions and confesses them to God. This may be done at all times, but is especially auspicious during the Ten Days of Awe and Repentance following the New Year. Therefore the prayers of these days include long confessions of sin and pleading for forgiveness, chanted by the congregation in unison.

In addition to confession and repentance, man must actively atone, or make up, for his misdeeds. The chief way of atoning is the fast, in which man “torments his flesh” and begs forgiveness. Yom Kippur, the Day of Atonement, is the chief fast day when observant Jews abstain from food and drink for 24 hours. Pious Jews, however, observe additional fast days. Mondays and Thursdays are favored for this purpose, since they are the days when the Torah is read in the synagogue. Any other day may be chosen for fasting, with the exception of Sabbath and holidays, when fasting is forbidden. When a fast day falls on a Sabbath its observance is postponed until the next day, except in the case of Yom Kippur, which takes precedence over the Sabbath.

In addition to the fasts of purification and atonement, there are a series of fast days that are associated with mournful events in Jewish history, especially with the fall of Jerusalem and the destruction of the Temple. Since it is believed that these catastrophes were punishments for the sins of Israel, such fast days are occasions for repentance as well as mourning. They are marked by fasting and the recitation of special prayers and lamentations. Their sadness, however, is tempered by faith that the Messiah was born on the day the Temple was destroyed, and will one day come to redeem the people of Israel from the misery of the exile that began with the Destruction.

The most mournful of these fast days, and the “blackest day in the Jewish calendar,” is Tisha b’Av, or the Ninth of Av. Tisha b’Av is the anniversary of the destruction of both Temples: the First by Nebuchadnezzar in 586 B.C.E., the Second by Titus in 70 C.E. The fast lasts from sundown of the eighth of Av to sunset the next day. During the morning hours until noon, both work and study are forbidden. The Book of Lamentations, the Prophet Jeremiah‘s outpouring of grief at the destruction of the First Temple, is chanted. Many kinnot, or lamentations, of later origin are also read. Some of these recall other calamities which befell Jews on this day, such as the massacres of whole Jewish communities during the Crusades.

Three other fasts are observed in commemoration of events connected with the destruction of the Temple. The 17th of Tammuz marks the day on which the enemy broke through the walls of Jerusalem and entered the city. The three-week interval between the 17th of Tammuz and Tisha b’Av are observed as weeks of mourning. The Fast of Gedaliah, on the third day of Tishri, commemorates the assassination of Gedaliah, the governor of Judea in the days that followed the destruction of the First Temple. After Gedaliah’s murder, the last vestiges of self-government were taken from the Jews. The 10th of Tevet was the day on which Nebuchadnezzar began the siege of Jerusalem. These three fast days are observed from sunrise to sunset, rather than from sundown of the preceding day to sunset of that day itself.