It is told of the Emperor Napoleon of France that he once passed the entrance of a synagogue in Paris on Tisha B'Av. When the Temple stood, Jerusalem was the bustling capital of Jewish activity and the focal point of all Jewish existence. At least 3 times a year, wherever they were, Jews would come to Jerusalem in honor of the pilgrim festivals, Pesach, Shavuot and Sukkot. The Holy City united the Jewish people and focused all their physical and spiritual endeavors towards G-d. Today, although the Temple no longer stands, Jerusalem is still the focal point of Jewish existence.
Numerous customs reflect the significance of Jerusalem in our lives.
At the festive occasion of a Jewish wedding, a glass is shattered in memory of Jerusalem, and it is customary to leave part of one's house, near its entrance, unpainted in honor of the Temple. It is customary to render a garment on seeing the ruins of Jerusalem. During the Three Weeks, the customs of mourning intensify as we commemorate the period when Jerusalem was besieged and the Temple razed to the ground. During this period we lessen the extent of our rejoicing. Marriages are not held during this three week period and we refrain from listening to music, dancing, taking pleasure trips, and from taking haircuts or shaving.