בְּעִנְיַן הַשִּׂמְחָה. On the topic of simchah.
עַל־פִּי מָשָׁל, שֶׁלִּפְעָמִים כְּשֶׁבְּנֵי־אָדָם שְׂמֵחִים וּמְרַקְּדִים, אֲזַי חוֹטְפִים אִישׁ אֶחָד מִבַּחוּץ, שֶׁהוּא בְּעַצְבוּת וּמָרָה שְׁחֹרָה, וּמַכְנִיסִים אוֹתוֹ בְּעַל־כָּרְחוֹ לְתוֹךְ מְחוֹל הַמְרַקְּדִים, וּמַכְרִיחִים אוֹתוֹ בְּעַל־כָּרְחוֹ שֶׁיִּהְיֶה שָׂמֵחַ עִמָּהֶם גַם־כֵּן; An analogy: Sometimes, when people are happy and dance, they grab someone standing outside [the circle] who is depressed and gloomy. Against his will they bring him into the circle of dancers; against his will, they force him to be happy along with them.
כֵּן יֵשׁ בְּעִנְיַן הַשִּׂמְחָה. כִּי כְּשֶׁאָדָם שָׂמֵחַ, אֲזַי הַמָּרָה שְׁחֹרָה וְיִסּוּרִים נִסְתַּלְּקִים מִן הַצַּד. It is the same with happiness. When a person is happy, gloom and suffering stand aside.
אֲבָל מַעְלָה יְתֵרָה – לְהִתְאַמֵּץ לִרְדֹּף אַחַר הַמָּרָה שְׁחֹרָה דַּוְקָא, לְהַכְנִיס אוֹתָהּ גַם־כֵּן בְּתוֹךְ הַשִּׂמְחָה, בְּאֹפֶן שֶׁהַמָּרָה שְׁחוֹרָה בְּעַצְמָהּ תִּתְהַפֵּךְ לְשִׂמְחָה. שֶׁיְּהַפֵּךְ הַמָּרָה שְׁחֹרָה וְכָל הַיִּסּוּרִין לְשִׂמְחָה, כְּדֶרֶךְ הַבָּא לְתוֹךְ הַשִּׂמְחָה, שֶׁאָז מִגֹּדֶל הַשִּׂמְחָה וְהַחֶדְוָה מְהַפֵּךְ כָּל הַדְּאָגוֹת וְהָעַצְבוּת וְהַמָּרָה שְׁחוֹרוֹת שֶׁלּוֹ לְשִׂמְחָה. נִמְצָא שֶׁחוֹטֵף הַמָּרָה שְׁחֹרָה וּמַכְנִיס אוֹתָהּ בְּעַל־כָּרְחָהּ לְתוֹךְ הַשִּׂמְחָה, כַּמָּשָׁל הַנַּ"ל. Yet greater still is to gather courage to actually pursue gloom, and to introduce it into the joy, such that the gloom itself turns into joy. A person should transform gloom and all suffering into joy. It is like a person who comes to a celebration. The abundant joy and happiness then, transforms all his worries, depression and gloom into joy. We find that he has grabbed the gloom and introduced it, against its will, into the joy, as in the aforementioned analogy.
וְזֶה בְּחִינַת (ישעיהו ל״ה:י׳): שָׂשׂוֹן וְשִׂמְחָה יַשִּׂיגוּ וְנָסוּ יָגוֹן וַאֲנָחָה – שֶׁהַיָּגוֹן וַאֲנָחָה בּוֹרְחִים וְנָסִים מִן הַשִּׂמְחָה, כִּי בְּעֵת הַשִּׂמְחָה דֶּרֶךְ הַיָּגוֹן וָאֲנָחָה לַעֲמֹד מִן הַצַּד כַּנַּ"ל, אֲבָל צָרִיךְ לִרְדֹּף אַחֲרֵיהֶם דַּיְקָא, וּלְהַשִּׂיגָם וּלְהַגִּיעָם, לְהַכְנִיס אוֹתָם דַּוְקָא לְתוֹךְ הַשִּׂמְחָה כַּנַּ"ל. This is the concept of “They will attain gladness and joy, as sadness and sighing flee” (Isaiah 35:10). The sadness and sighing flee and run from joy. For at a time of joy, it is the nature of sadness and sighing to stand aside. Yet one actually has to pursue them, and to catch-up with and reach them, in order to specifically introduce them into the joy.
וְזֶהוּ: שָׂשׂוֹן וְשִׂמְחָה יַשִּׂיגוּ וְכוּ' – שֶׁהַשָּׂשׂוֹן וְשִׂמְחָה יַשִּׂיגוּ וְיִתְפְּסוּ אֶת הַיָּגוֹן וַאֲנָחָה, שֶׁהֵם נָסִים וּבוֹרְחִים מִן הַשִּׂמְחָה, לְהַכְנִיס אוֹתָם בְּעַל־כָּרְחָם לְתוֹךְ הַשִּׂמְחָה כַּנַּ"ל. This is the meaning of “They will attain gladness and joy…” Gladness and joy will catch-up with and seize the sadness and sighing as they flee and run from joy, in order to introduce them, against their will, into the joy.
כִּי יֵשׁ יָגוֹן וַאֲנָחָה שֶׁהֵם הַסִּטְרָא־אָחֳרָא, שֶׁאֵינָם רוֹצִים לִהְיוֹת מֶרְכָּבָה אֶל הַקְּדֻשָּׁה, וְעַל־כֵּן הֵם בּוֹרְחִים מִן הַשִּׂמְחָה. עַל־כֵּן צָרִיךְ לְהַכְרִיחַ אוֹתָם לְהַכְנִיס אוֹתָם לְתוֹךְ הַקְּדֻשָּׁה, דְּהַיְנוּ הַשִּׂמְחָה, בְּעַל־כָּרְחָם, כַּנַּ"ל: For there are types of sadness and sighing that are [from] the Other Side. They do not want to be a vehicle for holiness, and so they flee from joy. Consequently, one needs to force them into the holiness, i.e., the joy, against their will.