- Peninei Halakha
The prophets established a fast day on the tenth of Tevet, because that is when Nebuchadnezzar and his army arrived to besiege Jerusalem, marking the beginning of the series of catastrophes that culminated in the destruction of the First Temple and the exile of the divine Presence. Though the siege that led to the destruction of the Second Temple began on a different date, nevertheless, the beginning of the overall destruction of the Temple and the Jewish kingdom occurred on the tenth of Tevet.
Once Asara Be-Tevet was established as a fast day, the Sages added two other painful events, which occurred around that date, to the day’s commemoration: the death of Ezra the Scribe, which occurred on the ninth of Tevet, and the translation of the Torah into Greek, which occurred on the eighth of Tevet. The Chief Rabbinate of Israel further established it as a day of general mourning and recitation of Kaddish (Yom Ha-Kaddish Ha-klali) for the martyrs who were killed in the Holocaust and whose date of death is unknown.
The Sages say that Ezra the Scribe was worthy of having the Torah given through him, had Moshe not preceded him (San. 21b). He is second in stature only to Moshe. Ezra enacted ten fundamental decrees (bk 82a), and, by doing so, laid the foundation for the activities of the Sages of the Oral Torah, who likewise made enactments and instituted safeguards to protect the Torah. The Sages further state that Ezra, who migrated from Babylonia to Eretz Yisrael to build the Second Temple, was actually the prophet Malachi (Megilla 15a). That is, on one hand, he was the last of the prophets, of those who belong to the era of the Written Torah; while on the other hand, he was the first Sage of the Oral Torah. Thus, he was the great Torah scholar who linked the Written Torah and Oral Torah. And just like Moshe, he cared for the people of Israel and bore the burden of leading them. He was one of the leaders of the return to Eretz Yisrael from Babylonia and one of the builders of the Second Temple.
Later on, during the Hellenistic period, a terrible decree was issued against the Jewish people: they must translate the Torah into Greek. That day was as calamitous for Israel as the day when the Golden Calf was made, because the Torah belongs to the Jewish people, and its translation into Greek undermined its uniqueness, allowing it to be viewed at something that anyone can handle. This occurred on the eighth of Tevet, causing darkness to descend upon the world for three days. Therefore, on Asara Be-Tevet, we mention this painful event as well.
My teacher and master, R. Zvi Yehuda Kook, said that we must rectify these three things on Asara Be-Tevet: 1) in response to the siege of Jerusalem, we must strengthen the walls of the city and build up Eretz Yisrael both spiritually and physically; 2) in response to the death of Ezra the Scribe, we must enhance and glorify the Torah while working to bring about the ingathering of the exiles, as Ezra did; 3) in response to the translation of the Torah into Greek, we must restore the authentic spirit and culture of Israel and uproot all the spirits of wickedness that accrued to it throughout the duration of the exile, when other nations ruled over us.