This letter discusses the holiness and care required in matters of permitted and forbidden foods, providing a Chabad spiritual framework for why food standards matter beyond bare legality.
אַךְ בֶּאֱמֶת, כְּשֶׁתְּדַקְדֵּק בִּלְשׁוֹן רַעְיָא מְהֵימְנָא דִלְעֵיל, ״וְאִילָנָא דְּטוֹב וָרָע דְּאִיהוּ אִיסּוּר וְהֶיתֵּר כוּ׳״, וְלֹא אָמַר ״תּוֹרַת אִיסּוּר וְהֶיתֵּר״ אוֹ ״הִלְכוֹת אִיסּוּר וְהֶיתֵּר״, אֶלָּא רוֹצֶה לוֹמַר, דְּגוּף דָּבָר הָאָסוּר וְדָבָר הַמּוּתָּר – הוּא מֵאִילָנָא דְטוֹב וָרָע, שֶׁהוּא קְלִיפַּת נוֹגַהּ, כְּמוֹ שֶׁכָּתוּב בְּעֵץ חַיִּים. וְזֶהוּ לְשׁוֹן ״אָסוּר״, שֶׁהַקְּלִיפָּה שׁוֹרָה עָלָיו וְאֵינוֹ יָכוֹל לַעֲלוֹת לְמַעְלָה כְּדָבָר הַ״מּוּתָּר״, דְּהַיְינוּ – שֶׁאֵינוֹ קָשׁוּר וְאָסוּר בִּקְלִיפָּה, וְיוּכַל לַעֲלוֹת עַל־יְדֵי הָאָדָם הָאוֹכְלוֹ בְּכַוָּונָה לַה׳, וְגַם בִּסְתָם, כָּל אָדָם הָעוֹבֵד ה׳ שֶׁבְּכֹחַ הָאֲכִילָה הַהִיא לוֹמֵד וּמִתְפַּלֵּל לַה׳, וְנִמְצָא שֶׁנַּעֲשָׂה אוֹתִיּוֹת הַתּוֹרָה וְהַתְּפִלָּה הָעוֹלָה לַה׳ – מִכֹּחַ הַנִּבְרָר מֵהַמַּאֲכָל הַהוּא. מַה־שֶּׁאֵין־כֵּן בִּדְבַר אִיסּוּר, שֶׁאֵינוֹ יָכוֹל לַעֲלוֹת לֹא בְּשַׁבָּת וְלֹא בְּחוֹל, גַּם כְּשֶׁמִּתְפַּלֵּל וְלוֹמֵד בַּכֹּחַ הַהוּא, אִם לֹא שֶׁאָכַל לְפִיקּוּחַ נֶפֶשׁ שֶׁהִתִּירוּ רַבּוֹתֵינוּ־זִכְרוֹנָם־לִבְרָכָה וְנַעֲשָׂה הֶיתֵּר [גָּמוּר].
But, in truth, when you will examine closely the above-quoted text of the Raaya Mehemna—“And the Tree of Good and Evil, i.e., prohibition and permission…” (you will note that) he did not say “the teaching of prohibition and permission” or “the laws of prohibition and permission.” Rather, he meant to say that “that which is prohibited,” and “that which is permitted” is of the Tree of Good and Evil, i.e., of kelipat nogah, as stated in Etz Chaim. That, too, is the etymological meaning of assur: the kelipah hovers over it and it cannot rise upward like that which is muttar, i.e., it is not tied and bound (assur) to the kelipah and is able to ascend by means of the person consuming it with his mind on G–d, or by any person serving G–d. For it is with the energy from this consumption that he studies and prays to G–d. Thus, from the energy extracted from that food are formed the the letters of Torah and of the prayers which ascend to G–d. It is otherwise with a proscribed matter. It cannot ascend, either on Shabbat or during the weekdays, even if one were to pray and study with that energy [unless one ate to save an endangered life, which is permitted by our Sages, of blessed memory, and becomes permissible (hetter)].