By: Louis Ginzberg
The Name:
The name "tanna" is derived from the Aramaic "teni" or "tena" (="to teach"), and designates in general a teacher of the oral law, and in particular one of the sages of the Mishnah, those teachers of the oral law whose teachings are contained in the Mishnah and in the Baraita. The term was first used in the Gemara to indicate a teacher mentioned in the Mishnah or in a baraita, in contradistinction to the later authorities, the Amoraim. Not all the teachers of the oral law who are mentioned in the Mishnah are called tannaim, however, but only those belonging to the period beginning with the disciples of Shammai and Hillel and ending with the contemporaries of Judah ha-Nasi I. The authorities preceding that period are called "zeḳenim ha-rishonim" (the former elders). In the time of the Amoraim the name "tanna" was given also to one well versed in the Mishnah and the other tannaitic traditions.
The period of the Tannaim, which lasted about 210 years (10-220 C.E.), is generally divided by Jewish scholars into five or six sections or generations, the purpose of such division being to show which teachers developed their principal activity contemporaneously. Some of the tannaim, however, were active in more than one generation. The following is an enumeration of the six generations and of the more prominent tannaim respectively belonging to them:
First Generation (10-80 C.E.):
Principal tannaim: the Shammaites (Bet Shammai) and the Hillelites (Bet Hillel), 'Aḳabya b. Mahalaleel, Rabban Gamaliel the Elder, Ḥanina, chief of the priests ("segan ha-kohanim"), Simeon b. Gamaliel, and Johanan b. Zakkai.
Second Generation (80-120):
Principal tannaim: Rabban Gamaliel II. (of Jabneh), Zadok, Dosa b. Harkinas, Eliezer b. Jacob, Eliezer b. Hyrcanus, Joshua b. Hananiah, Eleazar b. Azariah, Judah b. Bathyra.
Third Generation (120-140):
Principal tannaim: Ṭarfon, Ishmael, Akiba, Johanan b. Nuri, Jose ha-Gelili, Simeon b. Nanos, Judah b. Baba, and Johanan b. Baroḳa. Several of these flourished in the preceding period.
Fourth Generation:
This generation extended from the death of Akiba (c. 140) to that of the patriarch Simeon b. Gamaliel (c. 165). The teachers belonging to this generation were: Meïr, Judah b. Ilai, Jose b. Ḥalafta, Simeon b. Yoḥai, Eleazar b. Shammua, Johanan ha-Sandalar, Eleazar b. Jacob, Nehemiah, Joshua b. Ḳarḥa, and the above-mentioned Simeon b. Gamaliel.
Fifth Generation (165-200):
Principal tannaim: Nathan ha-Babli, Symmachus, Judah ha-Nasi I., Jose b. Judah, Eleazar b. Simeon, Simeon b. Eleazar.
Sixth Generation (200-220):
To this generation belong the contemporaries and disciples of Judah ha-Nasi. They are mentioned in the Tosefta and the Baraita but not in the Mishnah. Their names are: Polemo, Issi b. Judah, Eleazar b. Jose, Ishmael b. Jose, Judah b. Laḳish, Ḥiyya, Aḥa, Abba (Arika).
(ח) רַבָּן יוֹחָנָן בֶּן זַכַּאי קִבֵּל מֵהִלֵּל וּמִשַּׁמָּאי. הוּא הָיָה אוֹמֵר, אִם לָמַדְתָּ תוֹרָה הַרְבֵּה, אַל תַּחֲזִיק טוֹבָה לְעַצְמְךָ, כִּי לְכָךְ נוֹצָרְתָּ. חֲמִשָּׁה תַלְמִידִים הָיוּ לוֹ לְרַבָּן יוֹחָנָן בֶּן זַכַּאי, וְאֵלּוּ הֵן, רַבִּי אֱלִיעֶזֶר בֶּן הוֹרְקְנוֹס, וְרַבִּי יְהוֹשֻׁעַ בֶּן חֲנַנְיָה, וְרַבִּי יוֹסֵי הַכֹּהֵן, וְרַבִּי שִׁמְעוֹן בֶּן נְתַנְאֵל, וְרַבִּי אֶלְעָזָר בֶּן עֲרָךְ. הוּא הָיָה מוֹנֶה שִׁבְחָן. רַבִּי אֱלִיעֶזֶר בֶּן הוֹרְקְנוֹס, בּוֹר סוּד שֶׁאֵינוֹ מְאַבֵּד טִפָּה. רַבִּי יְהוֹשֻׁעַ בֶּן חֲנַנְיָה, אַשְׁרֵי יוֹלַדְתּוֹ. רַבִּי יוֹסֵי הַכֹּהֵן, חָסִיד. רַבִּי שִׁמְעוֹן בֶּן נְתַנְאֵל, יְרֵא חֵטְא. וְרַבִּי אֶלְעָזָר בֶּן עֲרָךְ, מַעְיָן הַמִּתְגַּבֵּר. הוּא הָיָה אוֹמֵר, אִם יִהְיוּ כָל חַכְמֵי יִשְׂרָאֵל בְּכַף מֹאזְנַיִם, וֶאֱלִיעֶזֶר בֶּן הוֹרְקְנוֹס בְּכַף שְׁנִיָּה, מַכְרִיעַ אֶת כֻּלָּם. אַבָּא שָׁאוּל אוֹמֵר מִשְּׁמוֹ, אִם יִהְיוּ כָל חַכְמֵי יִשְׂרָאֵל בְּכַף מֹאזְנַיִם וְרַבִּי אֱלִיעֶזֶר בֶּן הוֹרְקְנוֹס אַף עִמָּהֶם, וְרַבִּי אֶלְעָזָר בֶּן עֲרָךְ בְּכַף שְׁנִיָּה, מַכְרִיעַ אֶת כֻּלָּם:
(8) Rabban Yohanan ben Zakkai received [the oral tradition] from Hillel and Shammai. He used to say: if you have learned much Torah, do not claim credit for yourself, because for such a purpose were you created.
Rabban Yohanan ben Zakkai had five disciples and they were these: Rabbi Eliezer ben Hyrcanus, Rabbi Joshua ben Hananiah, Rabbi Yose, the priest, Rabbi Shimon ben Nethaneel and Rabbi Eleazar ben Arach. He [Rabbi Johanan] used to list their outstanding virtues: Rabbi Eliezer ben Hyrcanus is a plastered cistern which loses not a drop; Rabbi Joshua ben Hananiah happy is the woman that gave birth to him; Rabbi Yose, the priest, is a pious man; Rabbi Simeon ben Nethaneel is one that fears sin, And Rabbi Eleazar ben Arach is like a spring that [ever] gathers force.
§ The Gemara relates: Abba Sikkara was the leader of the zealots [biryonei] of Jerusalem and the son of the sister of Rabban Yoḥanan ben Zakkai. Rabban Yoḥanan ben Zakkai sent a message to him: Come to me in secret. He came, and Rabban Yoḥanan ben Zakkai said to him: Until when will you do this and kill everyone through starvation? Abba Sikkara said to him: What can I do, for if I say something to them they will kill me. Rabban Yoḥanan ben Zakkai said to him: Show me a method so that I will be able to leave the city, and it is possible that through this there will be some small salvation. Abba Sikkara said to him: This is what you should do: Pretend to be sick, and have everyone come and ask about your welfare, so that word will spread about your ailing condition. Afterward bring something putrid and place it near you, so that people will say that you have died and are decomposing. And then, have your students enter to bring you to burial, and let no one else come in so that the zealots not notice that you are still light. As the zealots know that a living person is lighter than a dead person.
Rabban Yoḥanan ben Zakkai did this. Rabbi Eliezer entered from one side and Rabbi Yehoshua from the other side to take him out. When they arrived at the entrance of the city on the inside, the guards, who were of the faction of the zealots, wanted to pierce him with their swords in order to ascertain that he was actually dead, as was the common practice. Abba Sikkara said to them: The Romans will say that they pierce even their teacher. The guards then wanted at least to push him to see whether he was still alive, in which case he would cry out on account of the pushing. Abba Sikkara said to them: They will say that they push even their teacher. The guards then opened the gate and he was taken out.
When Rabban Yoḥanan ben Zakkai reached there, i.e., the Roman camp, he said: Greetings to you [Vespasian, the Roman Emperor], the king; greetings to you, the king.
Vespasian said to him: You are liable for two death penalties, one because I am not a king and yet you call me king, and furthermore, if I am a king, why didn’t you come to me until now? Rabban Yoḥanan ben Zakkai said to him: As for what you said about yourself: I am not a king, in truth, you are a king, ... And as for what you said with your second comment: If I am a king why didn’t you come to me until now, there are zealots among us who did not allow us to do this.
Understanding that Rabban Yoḥanan ben Zakkai was prepared to ask him not to destroy the Temple, Vespasian said to him: If there is a barrel of honey and a snake [derakon] is wrapped around it, wouldn’t they break the barrel in order to kill the snake?...
In the meantime, as they were talking, a messenger [feristaka] arrived from Rome, and said to him: Rise, for the King has died, and the noblemen of Rome plan to appoint you as their leader and make you the next King.
Vespasian then said to Rabban Yoḥanan ben Zakkai: I will be going to Rome to accept my new position, and I will send someone else in my place to continue besieging the city and waging war against it. But before I leave, ask something of me that I can give you.
Rabban Yoḥanan ben Zakkai said to him: Give me Yavne and its Sages and do not destroy it, and spare the dynasty of Rabban Gamliel and do not kill them as if they were rebels, and lastly give me doctors to heal Rabbi Tzadok. Rav Yosef read the following verse about him, and some say that it was Rabbi Akiva who applied the verse to Rabban Yoḥanan ben Zakkai: “I am the Lord…Who turns wise men backward and makes their knowledge foolish” (Isaiah 44:25), as he should have said to him to leave the Jews alone this time.
Questions to ponder:
- What is the significance of the request "Give me Yavneh and its sages?"
- Why does Rabbi Akiva criticize/disagree with R. Yochanan ben Zakkai?
- How is R. Yochanan ben Zakkai portrayed as a flawed hero by the storyteller?
(ה) על גמ״ח כיצד הרי הוא אומר (הושע ו) כי חסד חפצתי ולא זבח. העולם מתחלה לא נברא אלא בחסד שנאמר (תהלים פט) כי אמרתי עולם חסד יבנה שמים תכין אמונתך בהם. פעם אחת היה רבן יוחנן בן זכאי יוצא מירושלים והיה רבי יהושע הולך אחריו וראה בית המקדש חרב [אר״י אוי לנו על זה שהוא חרב] מקום שמכפרים בו עונותיהם של ישראל. א״ל בני אל ירע לך יש לנו כפרה אחת שהיא כמותה ואיזה זה גמ״ח שנאמר כי חסד חפצתי ולא זבח שכן מצינו בדניאל איש חמודות שהיה מתעסק בגמ״ח ומה הן גמ״ח שהיה דניאל מתעסק בהם אם תאמר עולות וזבחים מקריב בבבל והלא כבר נאמר (דברים יב) השמר לך פן תעלה עולותיך בכל מקום אשר תראה כי אם במקום אשר יבחר ה׳ באחד שבטיך שם תעלה עולותיך. אלא מה הן גמ״ח שהיה מתעסק בהן היה מתקן את הכלה ומשמחה ומלווה את המת ונותן פרוטה לעני ומתפלל ג׳ פעמים בכל יום ותפלתו מתקבלת ברצון שנאמר (דניאל ו) ודניאל כדי ידע די רשים כתבא על לביתיה וכוין פתיחן ליה בעיליתה נגד ירושלם וזימנין תלתה ביומא הוא ברך על ברכוהי ומצלא ומודא קדם אלהה כל קבל די הוא עבד מן קדמת דנה. וכשבא אספסיינוס להחריב את ירושלים אמר להם שוטים מפני מה אתם מבקשים להחריב את העיר הזאת ואתם מבקשים לשרוף את בית המקדש וכי מה אני מבקש מכם אלא שתשגרו לי קשת אחת או חץ אחת ואלך [לי] מכם. אמרו לו כשם שיצאנו על שנים ראשונים שהם לפניך והרגנום כך נצא לפניך ונהרגך. כיון ששמע רבן יוחנן בן זכאי שלח וקרא לאנשי ירושלים ואמר להם בני מפני מה אתם מחריבין את העיר הזאת ואתם מבקשים לשרוף את בהמ״ק וכי מהו מבקש מכם הא אינו מבקש מכם אלא קשת אחת או חץ אחת וילך לו מכם. אמרו לו כשם שיצאנו על שנים שלפניו והרגנום כך נצא עליו ונהרגהו. היו לאספסיינוס אנשים שרויין כנגד חומותיה של ירושלים וכל דבר ודבר שהיו שומעין היו כותבין על החצי וזורקין חוץ לחומה לומר שרבן יוחנן בן זכאי מאוהבי קיסר הוא. [וכך היה מזכיר לאנשי ירושלים] וכיון שאמר [להם] רבי יוחנן בן זכאי יום אחד ושנים ושלשה ולא קבלו ממנו שלח וקרא לתלמידיו לר׳ אליעזר ורבי יהושע אמר להם בני עמדו והוציאוני מכאן עשו לי ארון ואישן בתוכו ר׳ אליעזר אחז בראשו ר׳ יהושע אחז (ברגליו והיו מוליכין אותו עד שקיעת החמה עד שהגיעו אצל שערי ירושלים. אמרו להם השוערים מי הוא זה אמרו להן מת הוא וכי אין אתם יודעין שאין מלינים את המת בירושלים אמרו להן אם מת הוא הוציאוהו) והוציאוהו (והיו מוליכין אותו עד שקיעת החמה) עד שהגיעו אצל אספסיינוס פתחו הארון ועמד לפניו. אמר לו אתה הוא ריב״ז שאל מה אתן לך א״ל איני מבקש ממך אלא יבנה אלך ואשנה בה לתלמידי ואקבע בה תפלה ואעשה בה כל מצות [האמורות בתורה] א״ל לך וכל מה שאתה רוצה לעשות עשה. א״ל רצונך שאומר לפניך דבר אחד א״ל אמור. א״ל הרי את עומד במלכות. מניין אתה יודע. א"ל כך מסור לנו שאין בהמ״ק נמסר ביד הדיוט אלא ביד המלך שנאמר (ישעיה י) ונקף סבכי היער בברזל והלבנון באדיר יפול. אמרו לא היה (יום אחד שנים) שלשה ימים עד שבא אליו דיופלא מעירו שמת קיסר ונמנו עליו לעמוד במלכות. הביאו לו קשת של זירים ותיפ״א כנגד החומה של ירושלים הביאו לו נסרים של ארז ונתן לתוך קשת של זירים והיה מכה בהן על החומה עד שפורץ בו פירצה הביאו ראש חזיר ונתנו לתוך קשת של זירים והיה משליך אותו כלפי איברים שע״ג המזבח. באותה שעה נלכדה ירושלים והיה רבן יוחנן בן זכאי יושב ומצפה וחרד (כנגד מקום) שהיה עלי יושב ומצפה שנאמר (ש״א ד) והנה עלי יושב על הכסא יד דרך מצפה כי היה לבו חרד על ארון האלהים. כיון ששמע רבן יוחנן בן זכאי שהחריב את ירושלים ושרף את בהמ״ק באש קרע בגדיו וקרעו תלמידיו את בגדיהם והיו בוכין וצועקין וסופדין ואומר (זכריה יא) פתח לבנון דלתיך [זה בהמ״ק] ותאכל אש בארזיך אלו כהנים (גדולים) שהיו במקדש שהיו [נוטלים] מפתחותן בידן וזורקין כלפי מעלה ואומרים לפני הקב״ה רבש״ע הילך מפתחותיך שמסרת לנו הואיל ולא היינו גזברין נאמנין לעשות מלאכת המלך ולאכול משלחן המלך . אברהם יצחק ויעקב וי״ב שבטים היו בוכין וצועקין וסופדין ואומרים (שם) הילל ברוש כי נפל ארז אשר אדירים שודדו [הילל בראש כי נפל ארז זה בית המקדש אשר אדירים שודדו זה אברהם יצחק ויעקב וי״ב שבטים] הילילו אלוני בשן זה משה אהרן ומרים כי ירד יער הבציר זה קודש הקדשים קול יללת הרועים כי [שדדה] אדרתם זה דוד ושלמה בנו קול שאגת כפירים כי שודד גאון הירדן זה אליהו ואלישע:
(5) When Vespasian came to destroy Jerusalem, he said to [the inhabitants]: Fools! Why do you seek to destroy this city and burn the Holy Temple? What do I request of you? Only that you give me one bow or one arrow [as a sign of your surrender], and then I will leave you be. They said to him: Just as we went out [to battle] against the two who came before you, and killed them, so will we go out against you and kill you.
When Rabban Yohanan ben Zakkai heard this, he sent for the men of Jerusalem and said to them: My children, why do seek to destroy this city and burn the Holy Temple? For what did he ask of you but one bow or one arrow, and then he would leave you be.
They said to him: Just as we went out [to battle] against the two who came before him, and we killed them, so will we go out against him and kill him. Vespasian had men lurking within the walls of Jerusalem, and everything they heard they would would write on an arrow and shoot over the wall. So they reported that Rabban Yohanan ben Zakkai supported the Caesar. [Thus would he remind the men of Jerusalem, i.e., plead with them to acquiesce to Vespasian.] And after Rabban Yohanan ben Zakkai said this [to them] day after day, and saw that they would not accept his advice, he sent for his students, Rabbi Eliezer and Rabbi Yehoshua, and said to them: My sons, take me out of this place! Make me a coffin, and I will sleep in it. So Rabbi Eliezer held [the coffin] on one end, and Rabbi Yehoshua held it (on the other, and they carried him until the sun set, right up to the gates of Jerusalem. The gatekeepers said to them: What is this? They replied: A dead body – and you know that a corpse cannot remain overnight in Jerusalem. They said: If that is a dead body, go ahead and take it out [of the city]). So they took him out (and they were carrying him until sunset) until they came to Vespasian, and they opened the coffin, and [Rabbi Yohanan] got up and stood before him.
He said: So you are Rabbi Yohanan ben Zakkai. Ask for whatever you wish, and I will give it to you. He replied: I ask nothing from you except for Yavneh. I will go there and teach my students, and I will establish prayer, and I will do all the mitzvot [mentioned in the Torah]. [Vespasian] replied: Go. All that you wish to do, you may do.
(א) יוֹם טוֹב שֶׁל רֹאשׁ הַשָּׁנָה שֶׁחָל לִהְיוֹת בְּשַׁבָּת, בַּמִּקְדָּשׁ הָיוּ תוֹקְעִים, אֲבָל לֹא בַמְּדִינָה. מְשֶּׁחָרַב בֵּית הַמִּקְדָּשׁ, הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי, שֶׁיְּהוּ תּוֹקְעִין בְּכָל מָקוֹם שֶׁיֶּשׁ בּוֹ בֵית דִּין. אָמַר רַבִּי אֶלְעָזָר, לֹא הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי אֶלָּא בְיַבְנֶה בִּלְבָד. אָמְרוּ לוֹ, אֶחָד יַבְנֶה וְאֶחָד כָּל מָקוֹם שֶׁיֶּשׁ בּוֹ בֵית דִּין:
(ג) בָּרִאשׁוֹנָה הָיָה הַלּוּלָב נִטָּל בַּמִּקְדָּשׁ שִׁבְעָה, וּבַמְּדִינָה יוֹם אֶחָד. מִשֶּׁחָרַב בֵּית הַמִּקְדָּשׁ, הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי שֶׁיְהֵא לוּלָב נִטָּל בַּמְּדִינָה שִׁבְעָה זֵכֶר לַמִּקְדָּשׁ, וְשֶׁיְּהֵא יוֹם הָנֵף כֻּלּוֹ אָסוּר:
(ד) בָּרִאשׁוֹנָה הָיוּ מְקַבְּלִין עֵדוּת הַחֹדֶשׁ כָּל הַיּוֹם. פַּעַם אַחַת נִשְׁתַּהוּ הָעֵדִים מִלָּבֹא, וְנִתְקַלְקְלוּ הַלְוִיִּם בַּשִּׁיר. הִתְקִינוּ שֶׁלֹּא יְהוּ מְקַבְּלִין אֶלָּא עַד הַמִּנְחָה. וְאִם בָּאוּ עֵדִים מִן הַמִּנְחָה וּלְמַעְלָה, נוֹהֲגִין אוֹתוֹ הַיּוֹם קֹדֶשׁ וּלְמָחָר קֹדֶשׁ. מִשֶּׁחָרַב בֵּית הַמִּקְדָּשׁ הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי, שֶׁיְּהוּ מְקַבְּלִין עֵדוּת הַחֹדֶשׁ כָּל הַיּוֹם. אָמַר רַבִּי יְהוֹשֻׁעַ בֶּן קָרְחָה, וְעוֹד זֹאת הִתְקִין רַבָּן יוֹחָנָן בֶּן זַכַּאי, שֶׁאֲפִלּוּ רֹאשׁ בֵּית דִּין בְּכָל מָקוֹם, שֶׁלֹּא יְהוּ הָעֵדִים הוֹלְכִין אֶלָּא לִמְקוֹם הַוָּעַד:
(1) If Yom Tov of Rosh Hashanah fell on Shabbat, they would blow the shofar in the Temple but not in the country. After the destruction of the Temple, Rabban Yohanan ben Zakai decreed that it should be blown [on Shabbat] in every place where there was a court. Rabbi Eliezer said: Rabban Yohanan ben Zakai decreed for Yavneh only. They said to him: both Yavneh and any place where there is a court.
(3) In earlier times the lulav was taken for seven days in the Temple, and in the provinces for one day only. When the temple was destroyed, Rabbi Yohanan ben Zakkai decreed that the lulav should be taken in the provinces for seven days in memory of the Temple, [He also decreed] that on the whole of the day of waving it be forbidden [to eat the new produce].
§ Having mentioned the prohibition against plastering, which is a sign of mourning over the destruction of the Temple, the Gemara discusses related matters. The Sages taught in a baraita (Tosefta, Sota 15:11): When the Temple was destroyed a second time, there was an increase in the number of ascetics among the Jews, whose practice was to not eat meat and to not drink wine.
Rabbi Yehoshua joined them to discuss their practice. He said to them: My children, for what reason do you not eat meat and do you not drink wine? They said to him: Shall we eat meat, from which offerings are sacrificed upon the altar, and now the altar has ceased to exist? Shall we drink wine, which is poured as a libation upon the altar, and now the altar has ceased to exist? Rabbi Yehoshua said to them: If so, we will not eat bread either, since the meal-offerings that were offered upon the altar have ceased. They replied: You are correct. It is possible to subsist with produce. He said to them: We will not eat produce either, since the bringing of the first fruits have ceased. They replied: You are correct. We will no longer eat the produce of the seven species from which the first fruits were brought, as it is possible to subsist with other produce. He said to them: If so, we will not drink water, since the water libation has ceased. They were silent, as they realized that they could not survive without water.
Rabbi Yehoshua said to them: My children, come, and I will tell you how we should act. To not mourn at all is impossible, as the decree was already issued and the Temple has been destroyed. But to mourn excessively as you are doing is also impossible, as the Sages do not issue a decree upon the public unless a majority of the public is able to abide by it, as it is written: “You are cursed with the curse, yet you rob Me, even this whole nation” (Malachi 3:9), indicating that the prophet rebukes the people for neglecting observances only if they were accepted by the whole nation.
Rabbi Yehoshua continues: Rather, this is what the Sages said: A person may plaster his house with plaster, but he must leave over a small amount in it without plaster to remember the destruction of the Temple. The Gemara interjects: And how much is a small amount? Rav Yosef said: One cubit by one cubit. Rav Ḥisda said: This should be opposite the entrance, so that it is visible to all. Rabbi Yehoshua continues: The Sages said that a person may prepare all that he needs for a meal, but he must leave out a small item to remember the destruction of the Temple. The Gemara interjects: What is this small item? Rav Pappa said: Something akin to small, fried fish. Rabbi Yehoshua continues: The Sages said that a woman may engage in all of her cosmetic treatments, but she must leave out a small matter to remember the destruction of the Temple. The Gemara interjects: What is this small matter? Rav said: She does not remove hair from the place on the temple from which women would remove hair. The source for these practices is a verse, as it is stated: “If I forget you, Jerusalem, let my right hand forget its cunning. Let my tongue cleave to the roof of my mouth, if I remember you not; if I set not Jerusalem above my highest joy” (Psalms 137:5–6). The Gemara asks: What is the meaning of: Above my highest [rosh] joy? Rav Yitzḥak says: This is referring to the burnt ashes that are customarily placed on the head [rosh] of bridegrooms at the time of their wedding celebrations, to remember the destruction of the Temple...
The baraita continues: And anyone who mourns for the destruction of Jerusalem will merit and see its joy, as it is stated: “Rejoice with Jerusalem, and be glad with her, all that love her; rejoice for joy with her, all that mourn for her” (Isaiah 66:10).