The Tenth of Teves is a communal fast day, commemorating the beginning of the siege of Jerusalem in the era of the First Beis HaMikdash, the Holy Temple. It's true that the tragic nature of the events commemorated by other fasts; the breaching of the walls of Jerusalem and the destruction of the Holy Temple, surpasses that of the Tenth of Teves. Nevertheless, since the siege of Jerusalem initiated the sequence of events that led to the destruction of the city and the Holy Temple, there is a dimension of severity to that fast which surpasses all others.

There is however, a favorable dimension of the Tenth of Teves. Our Sages teach that the present exile came as a result of unwarranted hatred. Similarly, had the bonds of oneness between the Jewish people been complete, the First Temple would not have been destroyed. For our Sages teach that when the unity of the Jewish people is consummate, no foe can overcome them.

During the time of a siege, all the inhabitants of a city are prevented from going about their personal business and are joined together as a single, collective entity. Regardless of their own feelings, the enemy forces them to come together as one.

This is the key to the Redemption. When we show unrestrained love for our fellowman, joining together with genuine unity, we will have erased the cause of the exile and then, the exile itself will cease. In this manner, the love and unity we can experience today serves as both a foretaste and a catalyst for the love and unity that will characterize the Era of the Redemption, when, as it is written, "there will be neither famine, nor war, neither envy nor competition."