The chapter on love of fellow Jews presents the mitzvah as rooted in the fact that their bodies are secondary to the shared divine soul. This strongly supports the idea that giving to another can arise from perceiving them as an extension of oneself.
וְהוּא, כַּאֲשֶׁר יָשִׂים אֶל לִבּוֹ מַה שֶּׁאָמַר הַכָּתוּב: ״כַּמַּיִם הַפָּנִים לַפָּנִים, כֵּן לֵב הָאָדָם אֶל הָאָדָם״; פֵּירוּשׁ, כְּמוֹ שֶׁכִּדְמוּת וְצוּרַת הַפָּנִים שֶׁהָאָדָם מַרְאֶה בַּמַּיִם, כֵּן נִרְאֶה לוֹ שָׁם בַּמַּיִם אוֹתָהּ צוּרָה עַצְמָהּ – כָּכָה מַמָּשׁ, ״לֵב הָאָדָם״ הַנֶּאֱמָן בְּאַהֲבָתוֹ לְאִישׁ אַחֵר, הֲרֵי הָאַהֲבָה זוֹ מְעוֹרֶרֶת אַהֲבָה בְּלֵב חֲבֵירוֹ אֵלָיו גַּם כֵּן, לִהְיוֹת אוֹהֲבִים נֶאֱמָנִים זֶה לָזֶה, בִּפְרָט כְּשֶׁרוֹאֶה אַהֲבַת חֲבֵירוֹ אֵלָיו. וְהִנֵּה, זֶהוּ טֶבַע הַנָּהוּג בְּמִדַּת כָּל אָדָם, אַף אִם שְׁנֵיהֶם שָׁוִים בְּמַעֲלָה. וְעַל אַחַת כַּמָּה וְכַמָּה, אִם מֶלֶךְ גָּדוֹל וְרַב, מַרְאֶה אַהֲבָתוֹ הַגְּדוֹלָה וְהָעֲצוּמָה לְאִישׁ הֶדְיוֹט וְנִבְזֶה וּשְׁפַל אֲנָשִׁים וּמְנֻוָּול הַמּוּטָּל בְּאַשְׁפָּה, וְיוֹרֵד אֵלָיו מִמְּקוֹם כְּבוֹדוֹ עִם כָּל שָׂרָיו יַחְדָּיו, וּמְקִימוֹ וּמְרִימוֹ מֵאַשְׁפָּתוֹ, וּמַכְנִיסוֹ לְהֵיכָלוֹ הֵיכַל הַמֶּלֶךְ, חֶדֶר לִפְנִים מֵחֶדֶר, מָקוֹם שֶׁאֵין כָּל עֶבֶד וְשַׂר נִכְנָס לְשָׁם, וּמִתְיַיחֵד עִמּוֹ שָׁם בְּיִחוּד וְקֵירוּב אֲמִיתִּי וְחִיבּוּק וְנִישּׁוּק וְאִתְדַּבְּקוּת רוּחָא בְּרוּחָא בְּכָל לֵב וָנֶפֶשׁ – עַל אַחַת כַּמָּה וְכַמָּה, שֶׁתִּתְעוֹרֵר מִמֵּילָא הָאַהֲבָה כְּפוּלָה וּמְכוּפֶּלֶת בְּלֵב הַהֶדְיוֹט וּשְׁפַל אֲנָשִׁים הַזֶּה אֶל נֶפֶשׁ הַמֶּלֶךְ, בְּהִתְקַשְּׁרוּת הַנֶּפֶשׁ מַמָּשׁ מִלֵּב וָנֶפֶשׁ מֵעוּמְקָא דְלִבָּא לְאֵין קֵץ, וְאַף אִם לִבּוֹ כְּלֵב הָאֶבֶן – הִמֵּס יִמַּס וְהָיָה לְמַיִם, וְתִשְׁתַּפֵּךְ נַפְשׁוֹ כַּמַּיִם – בִּכְלוֹת הַנֶּפֶשׁ מַמָּשׁ לְאַהֲבַת הַמֶּלֶךְ:
This [way] is to take to heart the meaning of the verse, “As water mirrors the reflection of a face, so is the heart of man to man.” This means that as [in the case of] the likeness and features of the face which a man presents to the water, the same identical face is reflected back to him from the water, so indeed is also the heart of a man who is loyal in his affection for another person, for this love awakens a loving response for him in the heart of his friend also, cementing their mutual love and loyalty for each other, especially as each sees his friend’s love for him. Such is the common nature in the character of every man, even when they are equal in status. How much more so when a great and mighty king shows his great and intense love for a commoner who is despised and lowly among men, a disgraceful creature cast on the dunghill, yet he [the king] comes down to him from the place of his glory, together with all his retinue, and raises him and exalts him from his dunghill and brings him into his palace, the royal palace, in the innermost chamber, a place such as no servant nor lord ever enters, and there shares with him the closest companionship with embraces and kisses and spiritual attachment with all heart and soul—how much more will, of itself, be aroused a doubled and redoubled love in the heart of this most common and humble individual for the person of the king, with a true attachment of spirit, heart, and soul, and with infinite heartfelt sincerity. Even if his heart be like a heart of stone, it will surely melt and become water, and his soul will pour itself out like water, with soulful longing for the love of the king.