2כְּדֶרֶךְ שֶׁאָסוּר לְהַלְווֹת כָּךְ אָסוּר לִלְווֹת בְּרִבִּית שֶׁנֶּאֱמַר (דברים כג כ) "לֹא תַשִּׁיךְ לְאָחִיךָ" מִפִּי הַשְּׁמוּעָה לָמְדוּ שֶׁזּוֹ אַזְהָרָה לַלּוֶֹה כְּלוֹמַר לֹא תִּנְשֹׁךְ לְאָחִיךְ. וְכֵן אָסוּר לְהִתְעַסֵּק בֵּין לוֶֹה וּמַלְוֶה בְּרִבִּית. וְכָל מִי שֶׁהָיָה עָרֵב אוֹ סוֹפֵר אוֹ עֵד בֵּינֵיהֶן הֲרֵי זֶה עוֹבֵר בְּלֹא תַּעֲשֶׂה. שֶׁנֶּאֱמַר (שמות כב כד) "לֹא תְשִׂימוּן עָלָיו נֶשֶׁךְ" זוֹ אַזְהָרָה אַף לָעֵדִים וְלָעָרֵב וְלַסּוֹפֵר. הָא לָמַדְתָּ שֶׁהַמַּלְוֶה בְּרִבִּית עוֹבֵר עַל שִׁשָּׁה לָאוִין. (שמות כב כד) "לֹא תִהְיֶה לוֹ כְּנשֶׁה". (ויקרא כה לז) "אֶת כַּסְפְּךָ לֹא תִתֵּן לוֹ בְּנֶשֶׁךְ". (ויקרא כה לז) "וּבְמַרְבִּית לֹא תִתֵּן אָכְלֶךָ". (ויקרא כה לו) "אַל תִּקַּח מֵאִתּוֹ נֶשֶׁךְ וְתַרְבִּית". לֹא תְשִׂימוּן עָלָיו נֶשֶׁךְ. (ויקרא יט יד) "וְלִפְנֵי עִוֵּר לֹא תִתֵּן מִכְשׁל". וְהַלּוֶֹה עוֹבֵר בִּשְׁנַיִם. לֹא תַשִּׁיךְ לְאָחִיךָ. וְלִפְנֵי עִוֵּר לֹא תִתֵּן מִכְשׁל. עָרֵב וְעֵדִים וְכַיּוֹצֵא בָּהֶן אֵין עוֹבְרִין אֶלָּא מִשּׁוּם לֹא תְשִׂימוּן עָלָיו נֶשֶׁךְ. וְכָל מִי שֶׁהָיָה סַרְסוּר בֵּין שְׁנֵיהֶם אוֹ שֶׁסִּיֵּעַ אֶחָד מֵהֶן אוֹ הוֹרָהוּ עוֹבֵר מִשּׁוּם לִפְנֵי עִוֵּר לֹא תִתֵּן מִכְשׁל:
Just as it is forbidden to give a loan at interest; so, too, it is forbidden to borrow at interest, as Deuteronomy, ibid., states: "Do not offer interest to your brother." According to the Oral Tradition, we learned that this is a warning to the borrower. Similarly, it is forbidden to act as a broker between the borrower and the lender when interest is involved. Anyone involved, a guarantor, a scribe or a witness transgresses a negative commandment, as Exodus 22:24 states: "Do not lay interest upon him." This is a warning against the witnesses, the guarantor and the scribe. Thus, we see that a person who offers a loan at interest violates six prohibitions: "Do not act like a creditor toward him," "Do not give him your money with neshech" "Do not put forth your food at marbit" "Do not take neshech and tarbit from him" (Leviticus 25:36 , "Do not lay interest upon him," and "Do not place a stumbling block in front of the blind" (Leviticus 19:14 . A person who borrows at interest violates two prohibitions: "Do not offer interest to your brother." "Do not place a stumbling block in front of the blind" The guarantor, the witnesses and the like violate only the prohibition: "Do not lay interest upon him." Any broker who connects between the lender and the borrower or assists or instructs one of them with regard to making the loan transgresses the commandment: "Do not place a stumbling block in front of the blind"