Ezra, head of the Sanhedrin and the leader of the Jewish people at the time of the building of the Second Temple, made an historic address to a three-day assemblage of Jews in Jerusalem, exhorting them to adhere to the teachings of the Torah and to dissolve their interfaith marriages (the Jewish people were on the verge of complete assimilation at the time, following their 70-year exile in Babylonia).
Links: On Intermarriage
The first printing of the "bible of Chassidism", the Tanya, the magnum opus of Rabbi Schneur Zalman of Liadi, founder of Chabad.
Links: The Longer Shorter Way; Lessons in Tanya (includes an English translation of the Hebrew text plus explanatory commentary in English)
The Rosh Hashanah ("new year") of Chassidism, marking the liberation of Rabbi Schneur Zalman of Liadi and the subsequent blossoming of Chabad Chassidism, is celebrated for two days, Kislev 19-20. (The Rebbe was released from prison on the 19th, but his full freedom was only obtained late in the evening -- Kislev 20 on the Jewish Calendar.) The two days are celebrated with farbrengens (Chassidic gatherings) and an increased commitment to the ways and teachings of Chassidism. Tachnun (supplication) and similar prayers are omitted. For more information and links, see entries for yesterday Kislev 19.
In Chabad practice, Tachanun (confession of sins) and similar prayers are omitted today.
Naturally, we think of the Jewish people as a conglomerate of many Jews. But the Baal Shem Tov saw the Jewish people as a single, indivisible whole.
Think of a geometrical point. A point is indivisible, but not because it is too hard, too big, or too small to cut up. A point simply has no area to be divided. That’s what makes it a point.
And yet, from a point you can extend infinite lines radiating in infinite dimensions.
In a somewhat similar way, but far beyond, all Jews are one Jew. Which means that in any one Jew, you will find all of us—just from a different angle.
So that whatever happens to any one of us instantaneously happens to the entire Jewish people. Not by some ripple effect or resonance. But because any one sample of the whole is the whole and the whole is one.
And so, the Baal Shem Tov taught, when the light of any one Jewish soul breaks free, the entire nation is redeemed along with it.
And accordingly, the Rebbe wrote, the ultimate exodus of our entire people is also a personal, intimate liberation for every Jew.