Asara B'Tevet and the Status of the Minor Fasts

As Rav Ḥana bar Bizna said that Rabbi Shimon Ḥasida said: What is the meaning of that which is written: “Thus said the Lord of hosts: The fast of the fourth month, and the fast of the fifth, and fast of the seventh, and the fast of the tenth, shall become times of joy and gladness, and cheerful seasons, to the house of Judah” (Zechariah 8:19). It calls them days of “fast” and it calls them “times of joy and gladness.” How so?

When there is peace in the world, they will be times of joy and gladness, on which eulogies and fasting are forbidden; but when there is no peace, they are days of fasting.

Rav Pappa said that this is what it is saying:

1)When there is peace in the world and the Temple is standing, these days will be times of joy and gladness;

2)when there is persecution and troubles for the Jewish people, they are days of fasting;

3)and when there is no persecution but still no peace, neither particular troubles nor consolation for Israel, the halakha is as follows: If people wish, they fast, and if they wish, they do not fast.

The Gemara asks: If so, the Ninth of Av should also be like the other fast days, that sometimes it is observed and sometimes not, depending upon the wishes of the community at the time. Why does the mishna state that messengers go out for the month of Av? Rav Pappa said: The Ninth of Av is different, since the calamities that occurred on that day were multiplied. As the Master said: On the Ninth of Av the Temple was destroyed, both the first one and the second one; on this day the city of Beitar was captured; and on this day the city of Jerusalem was plowed over by the enemies of the Jewish people, as a sign that it would never be rebuilt. Consequently, the fast of the Ninth of Av is obligatory, and not optional like the other fasts.