Seventeenth of Tammuz - Sources

Sources

The fast of Tammuz, according to Rabbi Akiva's interpretation, is the fast mentioned in the Book of Zechariah as "the fast of the fourth " (8:19 Mechon-Mamre.org Zechariah 8:19). This refers to Tammuz, which is the fourth month on the Hebrew calendar. This fast was originally on the ninth of Tammuz. After the destruction of the Second Temple, the fast was moved to the seventeenth.

According to the Mishnah (Taanit 4:6), five calamities befell the Jewish people on this day:

1. Moses broke the two tablets of stone on Mount Sinai;
2. The daily tamid offering ceased to be brought;
3. The walls of Jerusalem were breached (proceeding to the destruction of the Temple);
4. Prior to Bar Kokhba's revolt, Roman military leader Apostomus burned a Torah scroll;
5. An idol was erected in the Temple.

The Babylonian Talmud (Taanit 28b) places the second and fifth tragedies in the First Temple, while dating the third tragedy (breach of Jerusalem) to the Second Temple period.

Jerusalem of the First Temple, on the other hand, was breached on the 9th of Tammuz (cf. Jeremiah 39.2, 52.6–7). However, the Jerusalem Talmud (Taanit IV, 5) states that the breach of Jerusalem in the First Temple occurred on 17th Tammuz as well; the text in Jeremiah 39 is explained by stating that the Biblical record was "distorted", apparently due to the troubled times.