After nearly a month of fierce fighting inside Jerusalem (see "Today in Jewish History" for Tammuz 9), the armies of King Nebuchadnezzar of Babylonia broke through into the Temple compound, where they feasted and vandalized until the afternoon of Av 9, when they set the Holy Temple aflame.
Links: The Destruction of the Holy Temple
During the “Nine Days" from Av 1st to the Ninth of Av, we mourn the destruction of the Holy Temple. We abstain from meat and wine, music, haircutting, bathing for pleasure, and other joyous (and dangerous) activities. (The particular mourning customs vary from community to community, so consult a competent halachic authority for details.)
Consumption of meat and wine is permitted on Shabbat, or at a seudat mitzvah (obligatory festive meal celebrating the fulfillment of certain mitzvot) such as a brit (circumcision), or a siyum celebrating the completion of a course of Torah study (i.e., a complete Talmudic tractate). The Lubavitcher Rebbe, of righteous memory initiated the custom of conducting or participating in a siyum on each of the Nine Days (even if one does not avail oneself of the dispensation to eat meat).
Citing the verse "Zion shall be redeemed with mishpat [Torah] and its returnees with tzedakah," (Isaiah 1:27) the Rebbe urged that we increase in Torah study (particularly the study of the laws of the Holy Temple) and charity during this period.
Links:
Nine Days laws and customs
Daily live siyum broadcasts
Learn about the Holy Temple in Jerusalem
As impossible as it sounds, as absurd as it may seem: The mandate of darkness is to become light; the mandate of a busy, messy world is to find oneness.
We have proof, for the greater the darkness becomes, and the greater the confusion of life, the deeper our souls reach inward to discover their own light.
How could it be that darkness leads us to find a deeper light? That confusion leads us to find a deeper truth?
Only because the very act of existence is set to know its own author. That is the cosmic drama, its theme and its plot: That otherness should come to know oneness.
And we are the players in that drama.