Tisha B’Av, literally the ninth day of the Hebrew month of Av, is a day of mourning for the Jewish people. Several tragedies occurred on the ninth of the Hebrew month of Av, but the day was designated for mourning following the destruction of the holy Temples in Jerusalem.
The First Temple was destroyed on Tisha B’Av by the Babylonians in 3339, the Hebrew year since creation. The Second Temple was destroyed by the Romans in 3829.
Tisha B’Av marks the culmination of a three-week period of mourning, which began on the 17th of the Hebrew month of Tammuz, Shiva Asar B’Tammuz in Hebrew. Shiva Asar B’ Tammuz, like Tisha B’Av, is a fast day (though we fast from sunset on the eighth to nightfall on Tisha B’Av and only from sunrise to nightfall on Shiva Asar B’ Tammuz).
We observe the three weeks by not participating in weddings and other joyous events, not cutting our hair or purchasing new clothes. Beginning nine days before Tisha B’Av, we refrain from eating meat and listening to music.
On Tisha B’Av, we are careful to fast, not to bathe or oil ourselves, not to wear leather shoes, study Torah –– which is joyful –– or engage in sexual relations or other pleasurable acts with our spouse.