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
We all suffer a maddening delusion of being something separate from G‑d. The delusion of “I.”
We cannot heal it, because yes, we exist, for He created us.
We cannot live with it, because this chilling notion of otherness is a denial of the truth.
But we can resolve it in the act of learning Torah. In learning Torah, He speaks with us. If there were no other, with whom would He speak?
We can resolve it in prayer. In prayer, we speak with Him. If there were no other, who would speak with Him?
We can resolve it in every mitzvah. Through every mitzvah, we become one with Him. If there were no other, two would not become one.
Now the reality of our otherness is no longer simply a delusion, but a treasured artifact of a divine desire: that two should become one.
As Adam, the primal human, said, “This ‘I’ was created to serve its Creator.”