The seventeenth day of the Hebrew month of Tammuz and the ninth day of the Hebrew month of Av are days of fasting and mourning on the Jewish calendar. Here's why:
חמשה דברים אירעו את אבותינו בשבעה עשר בתמוז וחמשה בתשעה באב בשבעה עשר בתמוז נשתברו הלוחות ובטל התמיד והובקעה העיר ושרף אפוסטמוס את התורה והעמיד צלם בהיכל בתשעה באב נגזר על אבותינו שלא יכנסו לארץ וחרב הבית בראשונה ובשניה ונלכדה ביתר ונחרשה העיר משנכנס אב ממעטין בשמחה שבת שחל תשעה באב להיות בתוכה אסור מלספר ומלכבס ובחמישי מותרין מפני כבוד השבת ערב תשעה באב לא יאכל אדם שני תבשילין לא יאכל בשר ולא ישתה יין.
Five calamitous matters occurred to our forefathers on the seventeenth of Tammuz, and five other disasters happened on the Ninth of Av. On the seventeenth of Tammuz the tablets were broken by Moses when he saw that the Jews had made the golden calf; the daily offering was nullified by the Roman authorities and was never sacrificed again; the city walls of Jerusalem were breached; the general Apostemos publicly burned a Torah scroll; and Manasseh placed an idol in the Sanctuary.
On the Ninth of Av it was decreed upon our ancestors that they would all die in the wilderness and not enter Eretz Yisrael; and the Temple was destroyed the first time, in the days of Nebuchadnezzar, and the second time, by the Romans; and Beitar was captured; and the city of Jerusalem was plowed, as a sign that it would never be rebuilt.
Not only does one fast on the Ninth of Av, but from when the month of Av begins, one decreases acts of rejoicing. During the week in which the Ninth of Av occurs, it is prohibited to cut one’s hair and to launder clothes, but if the Ninth of Av occurs on a Friday, on Thursday these actions are permitted in deference to Shabbat. On the eve of the Ninth of Av a person may not eat two cooked dishes in one meal. Furthermore, one may neither eat meat nor drink wine.
As you can see, these fast days have mourning practices associated with them stretch from the first fast day - the sevententh of Tammuz - to the second one, which is on the 9th of Av. This is a span of three weeks, during which many Jews do not get haircuts, shave, make major purchases, wear new clothing, or celebrate weddings.
The mourning customs intensify during the nine day countdown to the Ninth of Av, when the month of Av begins. During the Nine Days, Jewish legal sources prohibit people from eating meat, drinking wine, bathing or swimming for pleasure, doing laundry, or celebrating joyous occasions. You can read more about these laws here.
But why should we care? These things happened so long ago...
כל המתאבל על ירושלים זוכה ורואה בשמחתה ושאינו מתאבל על ירושלים אינו רואה בשמחתה
Whoever mourns for Jerusalem will merit and see her future joy, and whoever does not mourn for Jerusalem will not see her future joy.
The Talmud says that being part of Jewish destiny means mourning together with our community in response to the tragedies of our past, as a way of preparing to rejoice together at our future moments of joy.
In the Narrow Places: Daily Inspiration for the Three Weeks
by Dr. Erica Brown
Suffering humanizes us. Ignoring suffering dehumanizes us. I don’t want to ruin my good mood by looking at that homeless person, so I turn away – and with that turning, I let go of my social responsibility to him. Attunement to suffering makes us more compassionate. It also helps us appreciate where we come from and all that it took to get us where we are. We have to remind ourselves that we don’t diminish our happiness when we spend a day or a few weeks meditating on the tragedies of history from which we emerged. We become more grateful, holding on tightly to our blessed lives because we can…
According to the Talmud, the event that led directly to the destruction of the Temple was an incident in which one person embarrassed another - publicly, and seemingly without real cause. The bitterness led to the person who had been targeted inciting a battle between the Romans and the Jews. This story has become emblematic of the ways in which interpersonal insensitivity and cruelty leads to destruction on a national scale.
אקמצא ובר קמצא חרוב ירושלים... אקמצא ובר קמצא חרוב ירושלים דההוא גברא דרחמיה קמצא ובעל דבביה בר קמצא עבד סעודתא אמר ליה לשמעיה זיל אייתי לי קמצא אזל אייתי ליה בר קמצא אתא אשכחיה דהוה יתיב אמר ליה מכדי ההוא גברא בעל דבבא דההוא גברא הוא מאי בעית הכא קום פוק אמר ליה הואיל ואתאי שבקן ויהיבנא לך דמי מה דאכילנא ושתינא אמר ליה לא אמר ליה יהיבנא לך דמי פלגא דסעודתיך אמר ליה לא אמר ליה יהיבנא לך דמי כולה סעודתיך א"ל לא נקטיה בידיה ואוקמיה ואפקיה אמר הואיל והוו יתבי רבנן ולא מחו ביה ש"מ קא ניחא להו איזיל איכול בהו קורצא בי מלכא אזל אמר ליה לקיסר מרדו בך יהודאי א"ל מי יימר א"ל שדר להו קורבנא חזית אי מקרבין ליה אזל שדר בידיה עגלא תלתא בהדי דקאתי שדא ביה מומא בניב שפתים ואמרי לה בדוקין שבעין דוכתא דלדידן הוה מומא ולדידהו לאו מומא הוא סבור רבנן לקרוביה משום שלום מלכות אמר להו רבי זכריה בן אבקולס יאמרו בעלי מומין קריבין לגבי מזבח סבור למיקטליה דלא ליזיל ולימא אמר להו רבי זכריה יאמרו מטיל מום בקדשים...
Jerusalem was destroyed on account of Kamtza and bar Kamtza...The Gemara explains: Jerusalem was destroyed on account of Kamtza and bar Kamtza. This is as there was a certain man whose friend was named Kamtza and whose enemy was named bar Kamtza. He once made a large feast and said to his servant: Go bring me my friend Kamtza. The servant went and mistakenly brought him his enemy bar Kamtza. The man who was hosting the feast came and found bar Kamtza sitting at the feast. The host said to bar Kamtza. That man is the enemy [ba’al devava] of that man, that is, you are my enemy. What then do you want here? Arise and leave. Bar Kamtza said to him: Since I have already come, let me stay and I will give you money for whatever I eat and drink. Just do not embarrass me by sending me out. The host said to him: No, you must leave. Bar Kamtza said to him: I will give you money for half of the feast; just do not send me away. The host said to him: No, you must leave. Bar Kamtza then said to him: I will give you money for the entire feast; just let me stay. The host said to him: No, you must leave. Finally, the host took bar Kamtza by his hand, stood him up, and took him out. After having been cast out from the feast, bar Kamtza said to himself: Since the Sages were sitting there and did not protest the actions of the host, although they saw how he humiliated me, learn from it that they were content with what he did. I will therefore go and inform [eikhul kurtza] against them to the king. He went and said to the emperor: The Jews have rebelled against you. The emperor said to him: Who says that this is the case? Bar Kamtza said to him: Go and test them; send them an offering to be brought in honor of the government, and see whether they will sacrifice it. The emperor went and sent with him a choice three-year-old calf. While bar Kamtza was coming with the calf to the Temple, he made a blemish on the calf’s upper lip. And some say he made the blemish on its eyelids, a place where according to us, i.e., halakha, it is a blemish, but according to them, gentile rules for their offerings, it is not a blemish. Therefore, when bar Kamtza brought the animal to the Temple, the priests would not sacrifice it on the altar since it was blemished, but they also could not explain this satisfactorily to the gentile authorities, who did not consider it to be blemished. The blemish notwithstanding, the Sages thought to sacrifice the animal as an offering due to the imperative to maintain peace with the government. Rabbi Zekharya ben Avkolas said to them: If the priests do that, people will say that blemished animals may be sacrificed as offerings on the altar... As a result, they did nothing, bar Kamtza’s slander was accepted by the authorities, and consequently the war between the Jews and the Romans began.
There are many more resources on Sefaria on this topic. Check out our topics page on Tisha B'Av for more materials, and feel free to get in touch ([email protected]) if you would like a guided tour!