Permission to Accept Interest
The purpose of the law is for banks to collect interest, and this is according to the law, according to which the bank can be seen as a 'partner' of the borrower in his future profits and not his creditor, therefore the money that it collects is considered to be his share in the partnership.
("And this is what is clear here. And here is a well-known thing, that in later generations they found the permission of the Rabbis to borrow money in the permission of the Isaka, a matter that was clearly explained in Samuch, and it is a wonder that we have not found any hint in the Torah to find the permission to prohibit this, and the foundation and basis on which the Sages saw the buildings is not explained. "The Pillars of the Covenant" - Torah Tamimah Ha'arot and called a chapter like this Ha'arot Ketzeb, and so on: "Once upon a time, God pressed a man in his hour of need and forgot to remember that he was his companion according to the covenant of the covenant" - Agnon/ City and its Fullness, 646)
Translation
Expression (Hebrew)
הֶתֵּר עִסְקָה
Definition (Hebrew)
הֶתֵּר הַמְּיֹעָד לַבַּנְקִים וְהַמְּאַפְשֵׁר לָהֶם לִגְבּוֹת רִבִּית וְזֹאת ע"פ הַנָּחָה לְפִיהָ יֵשׁ לִרְאוֹת בַּבַּנְק 'שֻׁתָּף' שֶׁל הַלּוֹוֶה בִּרְוָחָיו הָעֲתִידִיִּים וְלֹא נוֹשֶׁה שֶׁלּוֹ, לָכֵן הַכְּסָפִים שֶׁהוּא גֹּבַהּ נֶחֱשָׁבִים לְקַבָּלַת חֶלְקוֹ בְּשֻׁתָּפוּת.
("וְזֶה הוּא שֶׁמְּבֹאָר כָּאן. וְהִנֵּה דָּבָר יָדוּעַ הוּא, שֶׁבַּדּוֹרוֹת הָאַחֲרוֹנִים הִמְצִיאוּ הֶתֵּר הַלְוָאָה בְּרִבִּית בְּהֶתֵּר עִסְקָא שֶׁנְּבָאֵר עִנְיָנוֹ בְּסָמוּךְ, וְלִכְאוֹרָה דְּבַר פֶּלֶא הוּא שֶׁלֹּא מָצִינוּ כָּל רֶמֶז קַל בַּתּוֹרָה לְהַמְצָאַת הֶתֵּר לְאִסּוּר זֶה, וְלֹא נִתְבָּאֵר הַיְּסוֹד וְהַבָּסִיס עַל מָה רָאוּ חָזָ"ל לִבְנוֹת עַמּוּדֵי הַהֶתֵּר"-תּוֹרָה תְּמִימָה הֶעָרוֹת וַיִּקְרָא פֶּרֶק כֹּה הֶעָרָה קצב, וְכֵן: "שֶׁפַּעַם אַחַת הַלֹּהַּ לְאֶחָד בִּשְׁעַת דַּחֲקוֹ וְשָׁכַח לְהַזְכִּיר שֶׁהוּא מַלְוֶה לוֹ לְפִי הַיֶּתֶר עִסְקָא"- עַגְנוֹן/ עִיר וּמְלוֹאָהּ, 646)