The Alter Rebbe describes how the Jewish soul has a natural love for Torah because Torah and the neshamah share the same divine source. 'Ten chelkeinu bitoratecha' can thus be read as a plea to actualize the neshamah's innate bond with Torah — to receive one's heavenly-rooted portion from Above.
וְהִנֵּה, שְׁלֹשָׁה לְבוּשִׁים אֵלּוּ מֵהַתּוֹרָה וּמִצְוֹתֶיהָ, אַף שֶׁנִּקְרָאִים לְבוּשִׁים לְנֶפֶשׁ רוּחַ וּנְשָׁמָה עִם כָּל זֶה, גָּבְהָה וְגָדְלָה מַעֲלָתָם לְאֵין קֵץ וְסוֹף עַל מַעֲלַת נֶפֶשׁ רוּחַ וּנְשָׁמָה עַצְמָן, כְּמוֹ שֶׁכָּתוּב בַּזֹּהַר, דְּאוֹרַיְיתָא וְקוּדְשָׁא־בְּרִיךְ־הוּא כּוּלָּא חַד, פֵּירוּשׁ: דְּאוֹרַיְיתָא, הִיא חָכְמָתוֹ וּרְצוֹנוֹ שֶׁל הַקָּדוֹשׁ־בָּרוּךְ־הוּא, וְהַקָּדוֹשׁ־בָּרוּךְ־הוּא בִּכְבוֹדוֹ וּבְעַצְמוֹ – כּוּלָּא חַד, כִּי הוּא הַיּוֹדֵעַ וְהוּא הַמַּדָּע וְכוּ׳, כְּמוֹ שֶׁנִּתְבָּאֵר לְעֵיל בְּשֵׁם הָרַמְבַּ״ם. וּמֵאַחַר שֶׁהַתּוֹרָה וּמִצְוֹתֶיהָ מַלְבִּישִׁים כָּל עֶשֶׂר בְּחִינוֹת הַנֶּפֶשׁ וְכָל תַּרְיַ״ג אֵבָרֶיהָ מֵרֹאשָׁהּ וְעַד רַגְלָהּ, הֲרֵי כּוּלָּהּ צְרוּרָה בִּצְרוֹר הַחַיִּים אֶת ה׳ מַמָּשׁ, וְאוֹר ה׳ מַמָּשׁ מַקִּיפָהּ וּמַלְבִּישָׁהּ מֵרֹאשָׁהּ וְעַד רַגְלָהּ, כְּמוֹ שֶׁכָּתוּב: ״צוּרִי אֶחֱסֶה בּוֹ״, וּכְתִיב: ״כַּצִּנָּה רָצוֹן תַּעְטְרֶנּוּ״, שֶׁהוּא רְצוֹנוֹ וְחָכְמָתוֹ יִתְבָּרֵךְ הַמְלוּבָּשִׁים בְּתוֹרָתוֹ וּמִצְוֹתֶיהָ. וְלָכֵן אָמְרוּ: ״יָפָה שָׁעָה אַחַת בִּתְשׁוּבָה וּמַעֲשִׂים טוֹבִים בָּעוֹלָם הַזֶּה מִכָּל חַיֵּי עוֹלָם הַבָּא״, כִּי עוֹלָם הַבָּא הוּא שֶׁנֶּהֱנִין מִזִּיו הַשְּׁכִינָה, שֶׁהוּא תַּעֲנוּג הַהַשָּׂגָה, וְאִי אֶפְשָׁר לְשׁוּם נִבְרָא, אֲפִילוּ מֵהָעֶלְיוֹנִים, לְהַשִּׂיג, כִּי אִם אֵיזוֹ הֶאָרָה מֵאוֹר ה׳, וְלָכֵן נִקְרָא בְּשֵׁם ״זִיו הַשְּׁכִינָה״; אֲבָל הַקָּדוֹשׁ־בָּרוּךְ־הוּא בִּכְבוֹדוֹ וּבְעַצְמוֹ – לֵית מַחֲשָׁבָה תְּפִיסָא בֵיהּ כְּלָל, כִּי אִם כַּאֲשֶׁר תְּפִיסָא וּמִתְלַבֶּשֶׁת בַּתּוֹרָה וּמִצְוֹתֶיהָ, אֲזַי הִיא תְּפִיסָא וּמִתְלַבֶּשֶׁת בְּהַקָּדוֹשׁ־בָּרוּךְ־הוּא מַמָּשׁ, דְּאוֹרַיְיתָא וְקוּדְשָׁא־בְּרִיךְ־הוּא כּוּלָּא חַד.
Now these three “garments,” deriving from the Torah and its commandments, although they are called “garments” of the nefesh, ruach, and neshamah, their quality, nevertheless, is infinitely higher and greater than that of the nefesh, ruach, and neshamah themselves, as explained in the Zohar, because the Torah and the Holy One, blessed is He, are one. The meaning of this is that the Torah, which is the wisdom and will of the Holy One, blessed is He, and His glorious Essence are one, since He is both the Knower and the Knowledge, and so on, as explained above in the name of Maimonides. Thus, since the Torah and its commandments “clothe” all ten faculties of the soul with all its 613 organs from head to foot, it [the soul] is altogether truly bound up in the Bundle of Life with G–d, and the very light of G–d envelops and clothes it from head to foot, as it is written, “G–d is my Rock, I will take refuge in Him,” and it is also written, “You will envelop him with favor (ratzon—will) as with a shield,” that is to say, with His will and wisdom, blessed be He, which are clothed in His Torah and its commandments. Hence it has been said: “Better is one hour of repentance and good deeds in this world than the whole life of the World to Come.” For, the World to Come is that state where one enjoys the effulgence of the Divine Presence, which is the pleasure of comprehension, yet no created being—even celestial—can comprehend more than some reflection of the Divine light; that is why the reference is to “effulgence of the Divine Presence” (Ziv haShechinah). But as for the essence of the Holy One, blessed is He, no thought can apprehend Him at all, except when it apprehends, and is clothed in, the Torah and its mitzvot; only then does it truly apprehend, and is clothed in, the Holy One, blessed is He, inasmuch as the Torah and the Holy One, blessed is He, are one and the same.