Introduction
Jews don’t agree on everything, but “sitting shiva” is one practice shared across the different denominations - so much so that “shiva” actually appears in the Merriam-Webster dictionary! But where does this custom of intense mourning for seven days following the burial of one’s immediate relative come from?
The Babylonian and Jerusalem Talmuds find sources for shiva throughout the Tanakh and their prooftexts bring in biblical characters from different eras.
Here are some observations, and some questions to consider:
The Babylonian Talmud's Version
יָתֵיב רַבִּי חִיָּיא בַּר אַבָּא וְרַבִּי אַמֵּי וְרַבִּי יִצְחָק נַפָּחָא אַקִּילְעָא דְּרַבִּי יִצְחָק בֶּן אֶלְעָזָר נְפַק מִילְּתָא מִבֵּינַיְיהוּ מִנַּיִן לַאֲבֵילוּת שִׁבְעָה דִּכְתִיב וְהָפַכְתִּי חַגֵּיכֶם לְאֵבֶל מָה חַג שִׁבְעָה אַף אֲבֵילוּת שִׁבְעָה
וְאֵימָא עֲצֶרֶת דְּחַד יוֹמָא הָהוּא מִיבְּעֵי לֵיהּ לְכִדְרֵישׁ לָקִישׁ דְּאָמַר רֵישׁ לָקִישׁ מִשּׁוּם רַבִּי יְהוּדָה נְשִׂיאָה מִנַּיִן לִשְׁמוּעָה רְחוֹקָה שֶׁאֵינָהּ נוֹהֶגֶת אֶלָּא יוֹם אֶחָד דִּכְתִיב וְהָפַכְתִּי חַגֵּיכֶם לְאֵבֶל וְאַשְׁכְּחַן עֲצֶרֶת דְּאִיקְּרִי חַד יוֹמָא חַג
§ It was related that Rabbi Ḥiyya bar Abba, Rabbi Ami, and Rabbi Yitzḥak Nappaḥa were once sitting in the pavilion of Rabbi Yitzḥak ben Elazar and were conversing. A matter emerged from among them: From where is it derived that the rites of mourning are observed for seven days? As it is written: “And I will turn your Festivals into mourning” (Amos 8:10). Just as a Festival lasts for seven days, so too mourning lasts for seven days.
The Gemara asks: And say that perhaps mourning is like Shavuot, which is only one day. The Gemara rejects this argument: That derivation, from the one day of Shavuot, is required for what was stated by Reish Lakish, as Reish Lakish said in the name of Rabbi Yehuda Nesia: From where is it derived that mourning in the case of distant tidings, i.e., when one hears that one of his relatives died a long time ago, applies for only one day? As it is written: “And I will turn your Festivals into mourning,” and we find with regard to Shavuot that one day is also called a Festival.
The Jerusalem Talmud's Version
מְנַיִין לָאֵבֶל מִן הַתּוֹרָה שִׁבְעָה. וַיַּעַ֧שׂ לְאָבִ֛יו אֵבֶ֭ל שִׁבְעַ֥ת יָמִֽים׃ וּלְמֵידִין דָּבָר קוֹדֶם לְמַתַּן תּוֹרָה. רִבִּי יַעֲקֹב בַּר אָחָא בְשֵׁם רִבִּי זְעוּרָא שָׁמַע לָהּ מִן הָדָא. וּפֶ֩תַח֩ אוֹהֶל מוֹעֵ֜ד תֵּֽשְׁב֨וּ יוֹמָ֤ם וָלַ֨יְלָה֙ שִׁבְעַ֣ת יָמִ֔ים וּשְׁמַרְתֶּ֛ם אֶת־מִשְׁמֶ֥רֶת מִשְׁכַּן ײ֨. כְּשֵׁם שֶׁשִּׁימֵּר הַקָּדוֹשׁ בָּרוּךְ הוּא עַל עוֹלָמוֹ שִׁבְעָה. כָּךְ אַתֵּם שִׁמְרוּ עַל אֲחֵיכֶם שִׁבָעָה. וּמְנַיִין שֶׁשִּׁימֵּר הַקָּדוֹשׁ בָּרוּךְ הוּא עַל עוֹלָמוֹ שִׁבְעָה. וַיְהִ֖י לְשִׁבְעַ֣ת הַיָּמִ֑ים וּמֵ֣י הַמַּבּ֔וּל הָי֖וּ עַל־הָאָֽרֶץ. ומִּתְאַבְּלִין קוֹדֶם שֶׁיָּמוּת הַמֵּת. אֶלָּא בָשָׂר וָדָם שֶׁאֵינוֹ יוֹדֵעַ מֶה עָתִיד לִהְיוֹת אֵינוֹ מִתְאַבֵּל עַד שֶׁיָּמוּת הַמֵּת. אֲבָל הַקָּדוֹשׁ בָּרוּךְ הוּא שֶׁהוּא יוֹדֶעַ מֶה עָתִיד לִהְיוֹת שִׁימֵּר עַל עוֹלָמוֹ תְּחִילָּה. אִית דְּבָעֵי מֵימַר. אֵילּוּ שִׁבְעַת יְמֵי אֲבְלוֹ שֶׁלְמְתוּשֶׁלַח הַצַּדִּיק. אָמַר רִבִּי הוֹשַׁעְיָה. כִּי־שְׁ֛מֶן מִשְׁחַ֥ת י֙י עֲלֵיכֶ֑ם. כְּשֵׁם שֶׁנִּתְרַוִּיתֶם בְּשֶׁמֶן הַמִּשְׁחָה כָּל־שִׁבְעָה. כָּךְ אַתֶּם שִׁמְרוּ עַל אֲחֵיכֶם כָּל־שִׁבְעָה. רִבִּי אַבָּהוּ בְשֵׁם רִבִּי יוֹחָנָן. אַל־נָ֥א תְהִ֖י כַּמֵּ֑ת. תִּסָּגֵ֞ר. מַה יְמֵי הַמֵּת שִׁבְעָה אַף יְמֵי הֶסְגֵּר שִׁבְעָה. חַד בִּרְבִּי אֲמַר הָדָא דְרִבִּי יוֹחָנָן קוֹמֵי דְרִבִּי שִׁמְעוֹן בֶּן לָקִישׁ וְלָא קִיבֵּל עֲלוֹי. אֲמַר. הָכָא עֲבַד לָהּ לְהֶסְגֵּר. וְהָכָא עֲבַד לָהּ לְהֶחְלֵט. דְּאָמַר רִבִּי יוֹחָנָן בְּשֵׁם רִבִּי יַנַּיי. אַל־נָ֥א תְהִ֖י כַּמֵּ֑ת. מַה יְמֵי הַמֵּת אֵינָן עוֹלִין. אַף יְמֵי הֶחְלֵט אֵינָן עוֹלִין. רִבִּי יִרְמְיָה וְרִבִּי חִייָה בְשֵׁם רִבִּי שִׁמְעוֹן בֶּן לָקִישׁ. רִבִּי אַבָּהוּ רִבִּי יוֹסֵי בֶן חֲנִינָה בְשֵׁם רִבִּי שִׁמְעוֹן בֶּן לָקִישׁ. וַֽיִּתְּמ֔וּ יְמֵ֥י בְכִ֖י אֵ֥בֶל מֹשֶֽׁה׃ יְמֵ֥י שִׁבְעָה. בְכִ֖י שְׁנֵיִם. אֵ֥בֶל שְׁלֹשִׁים. וְאִית דִּמְחַלְּפִין. יְמֵ֥י שְׁנֵיִם. בְכִ֖י שִׁבְעָה. אֵ֥בֶל שְׁלֹשִׁים. רִבִּי יוֹסֵה רִבִּי חִייָה בְשֵׁם רִבִּי שִׁמְעוֹן בֶּן לָקִישׁ. רִבִּי יוֹנָה וְרִבִּי חִייָה וְרִבִּי שִׁמְעוֹן בֶּן לָקִישׁ בְּשֵׁם רִבִּי יוּדָן נְשִׂייָא. וְהָֽפַכְתִּ֨י חַגֵּיכֶ֜ם לְאֵ֗בֶל. מַה יְמֵי הַחַג שִׁבְעָה. אַף יְמֵי הָאֵבֶל שִׁבְעָה. אָמַר רִבִּי אִמִּי לְרִבִּי חִייָה בַּר בַּא. אוֹ מַה יְמֵי הַחַג שְׁמוֹנָה. אַף יְמֵי הָאֵבֶל שְׁמוֹנָה. אָמַר לֵיהּ. שְׁמִינִי רֶגֶל בִּפְנֵי עַצְמוֹ הוּא. אוֹ מַה הַעֲצֶרֶת יוֹם אֶחַד. אַף הָאֵבֶל יוֹם אֶחַד. אָמַר לֵיהּ. מִיכָּן לַשְּׁמוּעָה רְחוֹקָה. וְתַנֵּי כֵן. שְׁמוּעָה קְרוֹבָה יֵשׁ לָהּ שִׁבְעָה וּשְׁלֹשִׁים. וּרְחוֹקָה אֵין לָהּ שִׁבְעָה וּשְׁלֹשִׁים.
From where in the Torah that mourning is seven {days}? He organized seven days of mourning for his father. Can you infer anything from before the giving of the Torah? Rebbi Jacob bar Aḥa in the name of Rebbi Ze`ira understood it from the following: At the door of the Tent of Meeting you shall sit day and night for seven days, and keep the watch of the Eternal’ s sanctuary. Just as the Holy One, praise to Him, watched over His World for seven {days}, so you shall watch for your brothers for seven {days}. And from where that the Holy One, praise to Him, watched over His World for seven {days}? It was after seven days that the Deluge came over the world. May one mourn before the dying person dies? Only flesh and blood who do not know what will be in the future do not mourn until the dying person dies. But the Holy One, praise to Him, Who knows what will be in the future did first watch for His world. Some want to say, these are the seven days of mourning for Methusela the Just. Rebbi Hoshaia said, for the Eternal’s anointing oil is on you. Just as you were anointed with the anointing oil all of seven, so watch for your brothers all of seven. Rebbi Abbahu in the name of Rebbi Joḥanan: please let her not be like the dead. She shall be locked away. Just as the day of isolation for the dead are seven, so the days of quarantine are seven. One student reported this from Rebbi Joḥanan before Rebbi Simeon ben Laqish, who did not accept it. He said, here he uses it for isolation, but there he uses it for making absolute, as Rebbi Joḥanan said in the name of Rebbi Yannai, please let her not be like the dead: just as the days of the dead are not counted, so the days of being absolute are not counted. Rebbi Jeremiah and Rebbi Ḥiyya in the name of Rebbi Simeon ben Laqish; Rebbi Abbahu, Rebbi Yose ben Ḥanina in the name of Rebbi Simeon ben Laqish: the days of crying of the mourning for Moses ended. “The days”, seven. “Of crying”, two. “Mourning”, thirty. Some switch, “the days”, two, “of crying”, seven, “mourning”, thirty. Rebbi Yose, Rebbi Ḥiyya, and Rebbi Simeon ben Laqish in the name of Rebbi Judah the Patriarch: I shall turn your holiday into mourning. Since the days of Tabernacles are seven, also the days of mourning are seven. Rebbi Immi said to Rebbi Ḥiyya bar Abba: Maybe since the days of Tabernacles are eight, also the days of mourning are eight? He answered him, the eighth day is a separate holiday Or since Pentecost is one day, also mourning is one day? He answered him, from here about a deferred information. And it was stated such: Current information requires Seven and Thirty. Deferred information does not require Seven and Thirty.