"When it shall be difficult for you, all of these things [d'varim, also may be translated 'words'] will find you at the end of the days, and you shall return to the Lord your G-d and hearken to His voice." (Deuteronomy 4:30)
This past Thursday we all fasted to the bittersweet melody of the Scroll of Lamentations (Eicha) - angst-music 
Moses provides a quintessential outline of Jewish history.
whose haunting cadences rise from the depths of Jewish despair. But when mid-day arrived, we got up from off the ground, our lagging spirits suddenly lifted as we put on our t'fillin adornments and recited the blessing of "comfort" (nahem) within the Amidah, a process that changes the mood of mourning while confirming the prophetic words of Zachariah, "Thus says the Lord G-d of hosts: the fast of the... fifth month [Tisha B'Av]... shall be for the house of Judah rejoicing, gladness and festival...." (Zachariah 8:19).
But how is it possible that the great tragic day of the Ninth of Av, a date when both Temples were destroyed, can become an occasion for joyous reprieve, even if only in the afternoon hours? What can we possibly be happy about?
I believe the answer is to be found in this week's Biblical reading, wherein Moses provides a quintessential outline of Jewish history: settlement of Israel, corruption and idolatry, destruction and exile, assimilation - but then eventual return to G-d and His land, because "the Lord your G-d is a compassionate G-d who will not forget the covenant with your forbears which He has sworn to them." (Deuteronomy 4:25-31,38)
Indeed, we read these verses on the day of Tisha B'Av itself, the day in which we mark the loss of our national sovereignty. But at the same time we remember that, although both sacred temples and even our sacred cities were destroyed, our nation was not. Unlike other peoples whose loss of homeland signaled a concomitant loss of national identity (look high and low in the UN to see if you can find traces of the Amorites, the Canaanites, the Hittites, the Babylonians...) we, the people of Israel, remained the people of the Covenant, our Torah mandating our mission and the promise of our eventual return to the land. The fact is that our survival as a separate ethnic and cultural entity for nearly 2,000 years of exile is itself one of the greatest miracles in the scope of history.
I'd like to suggest that the seed for our ultimate rejoicing on the Ninth of Av is planted in the declaration, "when it shall be difficult for you, these things [words] will find you... and you shall return...." (4:30) I have chosen to translate the phrase kol hadevarim as "these words," emphasizing the idea that "these words" of the Torah shall find you in the depths of your suffering, in the midst of your exile and assimilation, and you shall return.
The source for this translation goes back to 1965, when Lincoln Square Synagogue, my first congregation, was housed in a small apartment on the West Side of Manhattan (150 West End Ave. 1D). One day, I noticed a middle-aged gentleman who would enter the synagogue-apartment towards the end of the Torah reading, remain standing near the door, and quickly leave after the sermon. But on the Shabbat of Vaetchanan he arrived towards the beginning of the reading and, as the aforementioned words were read, he fled in tears. I ran out after him.
He later told me that his name was Wolf Reichard and that he grew up in a family of pious Satmar Hassidim, but he completely gave up on religion when he graduated from the hell-hole called Auschwitz. Then, for some reason, when our small apartment-synagogue opened its door, he found himself attracted to the services, and despite his own private history of suffering he recognized a need emerging from his truest self.
Upon hearing the Torah reader chant, "When it shall be difficult for you, all of these words will find you... and you shall return," he knew he could no longer erase his past or escape from his future destiny. The words were an arrow into his heart and from then on he came to shul not only every Sabbath (from the beginning of services), but also every morning; and in celebration of his return, he generously provided our weekly Sabbath Kiddush.
In 1970, five years later, the truth of this translation was confirmed when the Lubavitcher Rebbe, of blessed memory, asked me to open underground yeshivas in the former Soviet Union. On my first day in Moscow, I met a young man in front of my hotel, Leonid Lunya Rigerman. (Lunya, who would play a pivotal role in the historic struggle for Soviet Jewry, would become a special friend.) When he spotted me wearing a kippah, he asked if I was a religious Jew; and when I responded that I try to be, he invited me to his 30th birthday party. 
He completely gave up on religion when he graduated from the hell-hole called Auschwitz.
That's where I received first-hand reports of the Leningrad trials (Communist show trials of a group of refuseniks accused of attempting to hijack a plane to Israel) and the extent of the virulent anti-Semitism in Russia. All of this described in perfect New York English, because it turned out that Lunya was born to Communist parents who in 1930 had made "aliyah" from Allerton Avenue in the Bronx to the Soviet Union. By the time we met he was already a committed Jew - a refusenik, keeping whatever mitzvot he could at great personal sacrifice.
He told me his story, how his transformation began because of words. A physicist, he worked in a special laboratory whose employees had the privilege of library study two hours each day. Suffering painful headaches, unable to concentrate, he decided he needed a bit of a break from his laboratory experiments, and found himself wandering over to the English shelf, which - in deference to American visitors - contained a Holy Bible. He began to read and when he got to the Joseph story, he became fascinated, especially the section which describes how Joseph went out in search of his brothers. That's when he realized the Torah was speaking to him; he too was searching for his brothers - and they were not to be found in the physics lab.
He hurried over to Archipova Street, where the synagogue was located (needless to say, his Communist parents never made him a Bar Mitzvah), joining a line which turned out to be waiting for matzah (that night was Seder night and the man in front of him explained that matzah was "our freedom bread"). He put the matzah in his pocket, said nothing to his family, ate his 'freedom bread' before going to sleep, and the next morning reported for work.
But his job at the physics lab was terminated. A hidden camera outside the synagogue had photographed his presence. Thus ended the life of Lunya the Communist and began the history of Lunya the Jew. The words of the Torah had found him, too.