17 Tammuz (Torah in a Minute)

Thus said the LORD of Hosts: The fast of the fourth month, the fast of the fifth month, the fast of the seventh month, and the fast of the tenth month shall become occasions for joy and gladness, happy festivals for the House of Judah; but you must love honesty and integrity.

(4) The seventeenth day of Tammuz (is a fast day) because five tragic events occured on that day: 1) the Tablets [of the Covenant] were broken by Moses, when he came down from Mount Sinai, as it is written in the Torah, and this occurred on the seventeenth day of Tammuz. 2) The continual daily sacrifices were abolished. 3) (The Romans) broke through the wall of Jerusalem during the destruction of the second Beis Hamikdash. Although, during the destruction of the first Beis Hamikdash, the wall was breached on the ninth of Tammuz, as it is written, "In the fourth month, on the ninth of the month, the famine was growing worse in the city, etc. then a breach was made in the city," (Jeremiah 52:6), but at the destruction of the second Beis Hamikdash, the breach was made on the seventeenth day of Tammuz, and the destruction of the second Beis Hamikdash affects us more deeply. (Furthermore, it is stated in the Jerusalem Talmud, that even at the destruction of the first Beis Hamikdash, the breach was made on the seventeenth, but that because of all the troubles, they made an error in the date). 4) The wicked Apostomos burned a Torah scroll. 5) An idol was placed in the Beis Hamikdash by some wicked people among the Jews, and this caused the destruction of the Beis Hamikdash and our exile.

(6) If any of these fast days occurs on Shabbat, it is postponed until after Shabbat. When the tenth of Tevet occurs on erev Shabbat (Friday), we fast that entire day.

(1) Since the Seventeenth of Tammuz, marks the beginning of the anguish of the destruction of the Beis Hamikdash, it is customary to observe a partial mourning, from that day until after Tishah beAv. It is proper for every God-fearing person to recite Tikun Chatzos (the special midnight order), daily, in the afternoon. No weddings are performed, ...

(3) It is the custom not to have the hair cut during these days, neither the hair of the head, nor of the beard nor of any part of the body. Adults are forbidden to give their children a haircut.

(8) There is a difference between the first three fast days and Tisha beAv (the ninth day of Av). On the first three fast days, you are permitted to have food during the preceding night until the break of dawn, if you did not have your regular sleep. If, however, you did have your regular sleep, you are forbidden to eat or drink afterwards, unless you planned to do so before going to sleep. ...