("17th of [the month of] Tammuz"). Fast day commemorating the breach made in the defense wall surrounding Jerusalem in 586 BCE; this led to the capture of the city by the Babylonians under Nebuchadnezzar three weeks later. The historical sources regarding these events, which culminated in the First Temple's destruction, are II Kings 25 and Jeremiah 52. They relate that the armies of Nebuchadnezzar breached the walls of Jerusalem on the ninth day of the fourth month (Tammuz). From this it seems likely that the fast was originally observed on the ninth, and not on the 17th of the month. This was the situation until Shivah Asar be-Tammuz--- together with other minor fasts, with the possible exception of Tishah Be-Av (the Ninth of Av)---was abolished after the construction of the Second Temple (cf. Zech. 8:19). With regard to the last days of the Second Temple in 70 CE, Josephus notes that the breach in the walls of Jerusalem was made on the 17th of Tammuz and that a fast was subsequently established on that date. When all the fasts commemorating the destruction of the First Temple were reintroduced, the rabbis decided that a fast on the 17th of the month would link both historical events.
Tradition also associates other sad events with this day. On the 17th of Tammuz, it is said, the first Tablets of the Law were shattered by Moses when he descended from Sinai and found the Israelites worshiping the Golden Calf. On this same date, the heathen Apostomos burned a Scroll of the Law and placed an idol in the Sanctuary (Ta'an. 4:6). These events probably occurred during the oppressive regime of Antiochus in the era of the Maccabees. The last misfortune associated with the 17th of Tammuz was the collapse of the sacrificial system in 70 CE. The prolonged Roman siege had made it increasingly difficult to provide the animals required and, once Jerusalem's walls had been breached, the daily sacrifices in the Temple came to an end.
The period from the Fast of Tammuz until the Fast of Av, known as the Three Weeks, is traditionally observed as a time of public mourning. The minor fast of 17 Tammuz commences at sunrise on the day itself and not on the previous night (see also Fasting and Fast Days). There are no restrictions on bathing or wearing leather shoes, and other laws may be relaxed without question if one's health is invilved. Special Torah readings are prescribed for both the Morning and the Afternoon Service. The passages read in the morning are Exodus 32:11-14 and 34:1-10. In the afternoon, these passages are repeated and then followed (in the Ashkenazi rite) by a Haftarah taken from Isaiah (55:6-56:8).
