The fast of the 9th of Av is the fact which is second-most in importance and in severity of restrictions, coming behind only Yom Kippur. In order to understand why this is so, we will, as we did by the fast of the 17th of Tamuz, consult the Mishna and Gemora.
The first mention that we find of this fast day appears in Zecharaia 8:19 which mentions “…the fast on the fifth….” As the fifth month counting from Nissan (which is referred to as the first month) is Av, the “fast of the fifth month” is the fast of the 9th of Av. The Mishna in the tractate of Ta’anis 4:6 explains that we fast because of the five tragedies that occurred on this day. The five are: The decree that our ancestors in the desert would not enter the land of Israel was issued; the first Temple was destroyed; the second Temple was destroyed; the city of Betar was conquered; the city of Jerusalem was plowed over.
In order to get a fuller understanding of what each of these events were, we will take a look at the Gemora and commentators.
1}The Decree that our ancestors in the desert would not enter the land of Israel
The Gemora in Ta’anis 29a gives a rather detailed chronicle of events leading up to the decree that the generation that left Egypt and was in the desert would not enter the land of Israel. The purpose of this chronicle is to show that the decree was issued on the 9th of Av.
Why was this decree made? A few weeks ago, we read in the weekly Torah portion of Shelach how Moshe sent spies to survey the land of Israel so they could then report on the condition of the land to the people. When the spies returned, instead of telling the people the praises of the land (such as the larger than normal produce) they gave a totally slanted and negative report. Their malicious report and horrifying predictions caused many Jews to become grief-stricken and lose their faith in G-d.
The Gemora tells us that when G-d heard the bitter weeping of the Jews about what they believed was to be their bitter end, He responded “You wept a weeping without cause. Therefore, I shall establish for you a weeping (on this day) for generations to come.” The weeping was clearly without cause. G-d had already promised to take the nation in to the land of Israel. While the report of the spies may have been disheartening, the people should have ignored the report, and instead had faith that G-d would keep His promise. The decree that G-d issued was that the nation would wander for 40 years in the desert, until all adult males of this generation died. Only then would their children enter the land of Israel. This decree was issued on the 9th of Av.
2} The Destruction of the First Temple
The Gemora takes notice of a discrepancy between two Biblical verses which date the destruction of the first Temple. The first, in Melachim (Kings) II 25:8-9 says that “…in the 5th month, on the seventh of the month, came Nebuzardan, captain of the executors, into Jerusalem, and he burned the house of Hashem….” From this verse, it appears the Temple was destroyed on the 7th of Av.
The second verse in Yirmiya (Jeremiah) 52:12 is, word for word, identical to the previous verse, except for the fact that it dates the occurrence as the “tenth of the month,” the 10th of Av. Hence, we have a problem. One verse says the destruction occurred on the 7th, the other on the 10th. Where does the 9th of Av come in?
The Gemora answers that on the 7th day, the Temple was overrun by the invaders, who entered the sanctuary and performed depraved acts there on the 7th and 8th days. Towards the end of the 9th day, the Temple was set on fire. The fire lasted the entire 10th day.
So, why do we fast on the 9th? Before the Gemora addresses this question, in mentions the opinion of Rabbi Yochanan on this topic. R’ Yochanan said that “If I had been present at the time when the Sages established the day as a fast, I would have established the 10th of Av as the day of the fast, as that was the day the Temple burnt for the most part.” The Sages disagreed and felt that the fast should be on the ninth. The Gemora explains that the opinion of the Sages was that it was better to fix the commemoration according to the beginning of the calamity (the 9th of Av, when the Temple was first set on fire), rather than according to the day on which the unfolding of the calamity itself occurred for the most part.
Rabbi Yehudah Prero