Rabbi Isaac Luria Ashkenazi, known as Ari HaKadosh ("The Holy Lion") passed away on the 5th of Av of the year 5332 from creation (1572 CE). Born in Jerusalem in 1534, he spent many years in secluded study near Cairo, Egypt. In 1570 he settled in Safed, where he lived for two years until his passing at age 38. During that brief period, the Ari revolutionized the study of Kabbalah, and came to be universally regarded as one of the most important figures in Jewish mysticism. It was he who proclaimed, "In these times, we are allowed and duty-bound to reveal this wisdom," opening the door to the integration of the teachings of Kabbalah--until then the province of a select few in each generation--into "mainstream" Judaism.
Links:
A Tale of Two Kabbalists
Fallen Sparks
What is Kabbalah?
About The Ari
R. Chaim Ozer Grodzinski served as rabbi of the prestigious Jewish community of Vilna, Lithuania, for over fifty years. He was a distinguished scholar, and he authored Achiezer, a collection of halachic responsa.
A devoted communal activist, R. Chaim Ozer worked together with the fifth and sixth Lubavitcher Rebbes, R. Sholom DovBer and R. Yosef Yitzchak Schneersohn, on many projects to ease the plight of Russian Jewry (such as the 1929 struggle to send matzah into the Soviet Union).
Link: The Rebbe Goes to Vilna
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
In Torah, we mirror on earth that which G‑d performs on every plane of reality.
If so, since the Torah prohibits dislocating even a single stone of the Holy Temple in Jerusalem, how could it be that G‑d brought the entire structure to ruins?
For it would certainly be absurd to imagine that the Assyrians or the Romans had the power to set fire to G-d’s house.
It must be that this was not an act of destruction. Rather, it was the initial phase of a much greater construction, one that would be eternally indestructible.
And for that to occur, the Temple had to be temporarily leveled to its foundations and G-d’s people had to be scattered to the furthest reaches of human habitation.
Why? Because as long as there is any place in this world that considers itself outside the realm of holiness, there remains a place for the destruction of G‑d’s Temple.
But in our exile, we meet face to face all that considers itself foreign to the divine. We grasp its reins, extract its poison, and channel its power.
This third and ultimate Temple, then, will be built of the outside turned inward, of darkness taught to shine, of the other converted to the One, of the most sinister enemy transformed to a faithful ally.
No opposition will remain in the universe. And so it will last forever.
Then we will see that in truth, there was never any destruction. There was only rebuilding, growth, and eternal, deep love.