Tzom Gedalia: When Did it Happen, and Why Do We Fast Today?

First read the pesukim in Zecharia which describe the Four Fast Days (not including Yom Kippur and Taanit Esther):

(יט) כֹּֽה־אָמַ֞ר יְהוָ֣ה צְבָא֗וֹת צ֣וֹם הָרְבִיעִ֡י וְצ֣וֹם הַחֲמִישִׁי֩ וְצ֨וֹם הַשְּׁבִיעִ֜י וְצ֣וֹם הָעֲשִׂירִ֗י יִהְיֶ֤ה לְבֵית־יְהוּדָה֙ לְשָׂשׂ֣וֹן וּלְשִׂמְחָ֔ה וּֽלְמֹעֲדִ֖ים טוֹבִ֑ים וְהָאֱמֶ֥ת וְהַשָּׁל֖וֹם אֱהָֽבוּ׃ (פ)

Zechariah 8:19

(19) ’Thus saith the Lord of hosts: The fast of the fourth month, and the fast of the fifth, and the fast of the seventh, and the fast of the tenth, shall be to the house of Judah joy and gladness, and cheerful seasons; therefore love ye truth and peace.

Which months are referred to by the navi Zecharia? Which might refer to Tzom Gedalia?

____________________________________________________________________

Now let's read the story in Tanach, which describes the death of Gedalia, governer of Judea after the First Beit HaMikdash had already been destroyed:

ירמיהו מ׳:י״ג-ט״ז

(יג) וְיֽוֹחָנָן֙ בֶּן־קָרֵ֔חַ וְכָל־שָׂרֵ֥י הַחֲיָלִ֖ים אֲשֶׁ֣ר בַּשָּׂדֶ֑ה בָּ֥אוּ אֶל־גְּדַלְיָ֖הוּ הַמִּצְפָּֽתָה׃ (יד) וַיֹּאמְר֣וּ אֵלָ֗יו הֲיָדֹ֤עַ תֵּדַע֙ כִּ֞י בַּעֲלִ֣יס ׀ מֶ֣לֶךְ בְּנֵֽי־עַמּ֗וֹן שָׁלַח֙ אֶת־יִשְׁמָעֵ֣אל בֶּן־נְתַנְיָ֔ה לְהַכֹּתְךָ֖ נָ֑פֶשׁ וְלֹא־הֶאֱמִ֣ין לָהֶ֔ם גְּדַלְיָ֖הוּ בֶּן־אֲחִיקָֽם׃ (טו) וְיוֹחָנָ֣ן בֶּן־קָרֵ֡חַ אָמַ֣ר אֶל־גְּדַלְיָהוּ֩ בַסֵּ֨תֶר בַּמִּצְפָּ֜ה לֵאמֹ֗ר אֵ֤לְכָה נָּא֙ וְאַכֶּה֙ אֶת־יִשְׁמָעֵ֣אל בֶּן־נְתַנְיָ֔ה וְאִ֖ישׁ לֹ֣א יֵדָ֑ע לָ֧מָּה יַכֶּ֣כָּה נֶּ֗פֶשׁ וְנָפֹ֙צוּ֙ כָּל־יְהוּדָ֔ה הַנִּקְבָּצִ֣ים אֵלֶ֔יךָ וְאָבְדָ֖ה שְׁאֵרִ֥ית יְהוּדָֽה׃ (טז) וַיֹּ֨אמֶר גְּדַלְיָ֤הוּ בֶן־אֲחִיקָם֙ אֶל־יוֹחָנָ֣ן בֶּן־קָרֵ֔חַ אַֽל־תעש [תַּעֲשֵׂ֖ה] אֶת־הַדָּבָ֣ר הַזֶּ֑ה כִּֽי־שֶׁ֛קֶר אַתָּ֥ה דֹבֵ֖ר אֶל־יִשְׁמָעֵֽאל׃ (ס)

Jeremiah 40:13-16

(13) Johanan son of Kareah, and all the officers of the troops in the open country, came to Gedaliah at Mizpah (14) and said to him, “Do you know that King Baalis of Ammon has sent Ishmael son of Nethaniah to kill you?” But Gedaliah son of Ahikam would not believe them. (15) Johanan son of Kareah also said secretly to Gedaliah at Mizpah, “Let me go and strike down Ishmael son of Nethaniah before anyone knows about it; otherwise he will kill you, and all the Judeans who have gathered about you will be dispersed, and the remnant of Judah will perish!” (16) But Gedaliah son of Ahikam answered Johanan son of Kareah, “Do not do such a thing: what you are saying about Ishmael is not true!”

ירמיהו מ״א:א׳-ג׳

(א) וַיְהִ֣י ׀ בַּחֹ֣דֶשׁ הַשְּׁבִיעִ֗י בָּ֣א יִשְׁמָעֵ֣אל בֶּן־נְתַנְיָ֣ה בֶן־אֱלִישָׁמָ֣ע מִזֶּ֣רַע הַ֠מְּלוּכָה וְרַבֵּ֨י הַמֶּ֜לֶךְ וַעֲשָׂרָ֨ה אֲנָשִׁ֥ים אִתּ֛וֹ אֶל־גְּדַלְיָ֥הוּ בֶן־אֲחִיקָ֖ם הַמִּצְפָּ֑תָה וַיֹּ֨אכְלוּ שָׁ֥ם לֶ֛חֶם יַחְדָּ֖ו בַּמִּצְפָּֽה׃ (ב) וַיָּקָם֩ יִשְׁמָעֵ֨אל בֶּן־נְתַנְיָ֜ה וַעֲשֶׂ֥רֶת הָאֲנָשִׁ֣ים ׀ אֲשֶׁר־הָי֣וּ אִתּ֗וֹ וַ֠יַּכּוּ אֶת־גְּדַלְיָ֨הוּ בֶן־אֲחִיקָ֧ם בֶּן־שָׁפָ֛ן בַּחֶ֖רֶב וַיָּ֣מֶת אֹת֑וֹ אֲשֶׁר־הִפְקִ֥יד מֶֽלֶךְ־בָּבֶ֖ל בָּאָֽרֶץ׃ (ג) וְאֵ֣ת כָּל־הַיְּהוּדִ֗ים אֲשֶׁר־הָי֨וּ אִתּ֤וֹ אֶת־גְּדַלְיָ֙הוּ֙ בַּמִּצְפָּ֔ה וְאֶת־הַכַּשְׂדִּ֖ים אֲשֶׁ֣ר נִמְצְאוּ־שָׁ֑ם אֵ֚ת אַנְשֵׁ֣י הַמִּלְחָמָ֔ה הִכָּ֖ה יִשְׁמָעֵֽאל׃

Jeremiah 41:1-3

(1) In the seventh month, Ishmael son of Nethaniah son of Elishama, who was of royal descent and one of the king’s commanders, came with ten men to Gedaliah son of Ahikam at Mizpah; and they ate together there at Mizpah. (2) Then Ishmael son of Nethaniah and the ten men who were with him arose and struck down Gedaliah son of Ahikam son of Shaphan with the sword and killed him, because the king of Babylon had put him in charge of the land. (3) Ishmael also killed all the Judeans who were with him—with Gedaliah in Mizpah—and the Chaldean soldiers who were stationed there.

According to the pesukim above, when was Gedalia killed? Why do you think his murder was important enough for us to establish a fast day?

____________________________________________________________________

Next read the following Gemara:

ראש השנה י״ח ב:ה׳

צום השביעי זה ג' בתשרי שבו נהרג גדליה בן אחיקם ומי הרגו ישמעאל בן נתניה הרגו ללמדך ששקולה מיתתן של צדיקים כשריפת בית אלהינו

Rosh Hashanah 18b:5

“The fast of the seventh,” this is the third of Tishrei, on which Gedaliah, son of Ahikam, was killed. And who killed him? Ishmael, son of Nethaniah, killed him. The Sages established a fast to commemorate Gedaliah’s death to teach you that the death of the righteous is equivalent to the burning of the Temple of our Lord.

From the above Gemara, on what exact day does it sound like Gedalia was killed?

____________________________________________________________________

Now read the classic commentary Radak:

רד"ק ירמיהו פרק מא

(א) ויהי בחדש השביעי... ובר"ה נהרג גדליה בן אחיקם וקבעו התענית במוצאי ר"ה מפני שהוא י"ט:

According to Radak, on what exact day does it sound like Gedalia was killed? Why do you think this makes Tzom Gedalia so significant?

____________________________________________________________________