שֶׁלֹּא יִתֵּן הַלֹּוֶה רִבִּית לְיִשְׂרָאֵל – שֶׁנִּמְנַעְנוּ מִלָּתֵת רִבִּית לְיִשְׂרָאֵל (עי' ספהמ"צ להרמב"ם לאוין רלו), וּכְמוֹ כֵן גַּם מִלָּקַחַת אוֹתוֹ, וְעַל זֶה נֶאֱמַר (דברים כג כ) לֹא תַשִּׁיךְ לְאָחִיךָ נֶשֶׁךְ כֶּסֶף נֶשֶׁךְ אֹכֶל נֶשֶׁךְ כָּל דָּבָר וְגוֹ'. וּבָא הַפֵּרוּשׁ עַל זֶה, לֹא תַשִּׁיךְ לֹא תִּנָּשֵׁךְ, כְּלוֹמַר לֹא תִּתֵּן רִבִּית, שֶׁהַנּוֹתְנוּ הוּא הַנָּשׁוּךְ, וּבְבֵאוּר אָמְרוּ בְּפֶרֶק אֵיזֶהוּ נֶשֶׁךְ (ב"מ עה, ב) הַלֹּוֶה עוֹבֵר מִשּׁוּם לֹא תַשִּׁיךְ, וּמִשּׁוּם וְלִפְנֵי עִוֵּר לֹא תִתֵּן מִכְשֹׁל (ויקרא יט, יד). וְאִלּוּ לֹא בָּאָה הַמְּנִיעָה מְפֹרֶשֶׁת עַל זֶה הָיִיתִי סָבוּר שֶׁהַמַּלְוֶה הוּא שֶׁאָסוּר לְקַחְתּוֹ, אֲבָל הַלֹּוֶה אִם רָצָה לִמְחֹל וְרוֹצֶה בְּאוֹנָאָתוֹ שֶׁיְּהֵא מֻתָּר, כְּעִנְיַן אוֹנָאָה שֶׁהַמְּאַנֶּה הוּא עוֹבֵר לֹא הַמִּתְאַנֶּה. That the borrower not give interest to an Israelite: That we have been prevented from giving interest to an Israelite (see Sefer HaMitzvot, Negative Commandments 236), and, so too, from taking it. And about this is it stated (Deuteronomy 23:20), “You shall not take interest from your brother, interest of money, interest of food, interest of any thing, etc.” And the [traditional] explanation comes about this: “Do not take interest” means do not have interest taken from you, which is to say, do not give interest — as the one who gives it is the one who has it taken from him. And in the elucidation, they said in the chapter [entitled] Eizehu Neshekh (Bava Metzia 75b) [that] the borrower transgresses “Do not take interest” and “you shall not place a stumbling block before the blind” (Leviticus 19:14). And had this preventing of this not come explicitly, I would have reasoned that it is the lender that is forbidden from taking it, but [that] if the borrower wants to forgive and is willing to be oppressed, that it would be permitted — in the manner of [other] oppression, where it is the oppressor that is transgressing, not the oppressed.
מִשָּׁרְשֵׁי אִסּוּר הָרִבִּית וְהַרְחָקָתוֹ מִבְּנֵי יִשְׂרָאֵל כָּתַבְתִּי בּוֹ מָה שֶׁיָּדַעְתִּי בְּסֵדֶר מִשְׁפָּטִים (מצוה סח) וּבְסֵדֶר בְּהַר סִינַי (מצוה שמג), קְצָת דִּינֵי הָרִבִּית כְּמִנְהָגִי וְכָל הַצָּרִיךְ לְמִצְוָה זוֹ כְּמִנְהַג הַסֵּפֶר, וְקָחֶנּוּ מִשָּׁם. I have written what I know from the roots of the prohibition of interest and its distancing from the Children of Israel in the Order of Mishpatim (Sefer HaChinukh 68). And in the Order of Behar Sinai (Sefer HaChinukh 343), [I have written] a little of the laws of interest — as is my custom — and all that is needed for this commandment, as is the custom of the book. And take it from there.