In constructing the tapestry of law needed to engage the hearts and souls of the surviving Jews condemned to exile, the rabbis had to grapple with the enormous dilemma facing future generations. Certainly the earliest survivors, their visions scorched by the dying embers of the burning temple, would mourn its loss with a real yearning.
Jewish history attests that the method devised by the rabbis succeeded.
If we analyze how Jews conduct their lives during the three weeks between the 17th of Tammuz, the day Jerusalem's 'impregnable' walls were breached, and the 9th of Av, the day when the first and second temple went up in flames, we may learn the secret of the rabbis' genius. What we find are stages in the process of mourning. The first of Av marks the second rung of mourning. For nine days, excluding the Sabbath, meat is not eaten, wine is not drunk, clothes are not freshly laundered, and swimming for pleasure is forbidden. The most intense expression of mourning is reserved for the 9th of Av itself, a 24 hour fast day like Yom Kippur.