First printing of the Zohar, the fundamental work of the Kabbalah (Jewish esoteric and mystical teachings), authored by the Talmudic sage, Rabbi Shimon Bar Yochai.
Links: The Kabbalah
Av 20 is the yahrtzeit (anniversary of the passing) of the Lubavitcher Rebbe's father, Rabbi Levi Yitzchak Schneerson (1878-1944), in Alma Ata, Kazakhstan. Rabbi Levi Yitzchak was Chief Rabbi of Yekaterinoslav (currently Dnepropetrovsk), and was arrested and exiled to Kazakhstan by the Stalinist regime as a result of his work to preserve Jewish life in the Soviet Union.
Links:
A Brief Biography
Rebbetzin Chana Scneerson's biography, which includes her account of her husband's heroism, arrest and passing.
Looking at your world from Above, all is good.
Looking at your world from within, things don’t always look so nice.
Until you connect your world below to the world above. Then the goodness flows downward without distortion.
How do you make that connection? By clinging tightly above.
By putting all your trust in G‑d.