The Gemara (Ta’anit 30b) states that anyone who eats or drinks on Tisha Be’av shall not merit seeing the joy of Jerusalem and anyone who mourns over Jerusalem “merits and sees its joy” as the verse (Yeshaya 66) states, “Gladden Jerusalem and rejoice in her all those who love her; rejoice for joy with her all those who mourned for her.”
Maran Rabbeinu Ovadia Yosef zt”l analyzes the language of the Gemara, for our Sages first state that one who does not mourn over Jerusalem “shall not merit seeing its joy” in future tense and later, it states that one who mourns over Jerusalem “merits and sees its joy” in present tense. Why then did our Sages change the tense within the same sentence? It would seem more logical for them to have written that one who mourns over Jerusalem “shall merit seeing its joy” as it did above!
Maran zt”l explains that Hashem has decreed that a deceased individual be forgotten from one’s heart after a period of twelve months (as mourners are usually comforted following the loss of a loved one after twelve months when the pain has gradually subsided).
For this reason, when Yaakov Avinu mistakenly thought that his son, Yosef, had been torn apart by a wild animal, the verse (Bereshit 37) states, “And all of his sons and all of his daughters arose to console him, but he refused to be consoled.” Yaakov Avinu continued mourning the loss of his son for several years, because there is no decree that one who is alive be forgotten after twelve months and Yosef was very much alive.
Thus, the same applies to mourning the loss of the Bet Hamikdash in that although many years have passed since its destruction (1,947 years to be exact), we continue to mourn over it bitterly, for the Heavenly Bet Hamikdash is alive and continues to exist, as the verse states, “The sanctuary, Hashem, which Your hands have established” and the Third Bet Hamikdash, which we pray will be built speedily and in our days, will descend from Heaven already built. When one mourns over Jerusalem, this is actually a good sign in that “one merits and sees its joy,” for the mere fact that one is currently mourning over Jerusalem shows that the Bet Hamikdash is alive and well within him and he will share in its joy in the future. Indeed, our Sages taught that Mashiach son of David is born on Tisha Be’av, meaning that in the midst of our mourning over Jerusalem, the lights of the impending redemption already begin to shine.
The prophet (Zecharia 8) states: “So says Hashem, G-d 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 be for the house of Yehuda for joy, gladness, and good times; and love truth and peace.” We derive from this verse that all fast days observed in commemoration of the destruction of the Bet Hamikdash will eventually be abolished and turned into days of joy and merriment in the times of the Mashiach. Indeed, Maranzt”l concludes the laws of mourning (in his Chazon Ovadia-Avelut, Part 3, page 420) with the verse (Yeshaya 60): “Your sun shall no longer set and neither shall your moon withdraw, for Hashem shall be your everlasting light and the days of your mourning shall end. Your smallest shall become a thousand and your least a mighty nation; I Hashem shall hasten it in its time. You shall be a crown of glory in the hand of Hashem and a royal diadem in the palm of your G-d.” May we soon merit the fulfillment of these verses, Amen!