"You shall not be to him as a creditor" — to the poor man who is with you you shall not be as a creditor. "You shall not be to him as a creditor" — that you should not show yourself to him at all times [pressing for payment]. "You shall not lay interest upon him." Why does Scripture state this? Because it says, "You shall not give your money to him at interest," which is a warning to the lender not to lend at interest. Or is it only a warning to the borrower? When it says, "Do not take interest from him" (Leviticus 25:36), that is the warning to the borrower; so what does "your money" teach? It is a warning to the lender. I have only a warning for the lender and the borrower; from where do I include the guarantor, the witnesses, and the scribe? Scripture teaches, "You shall not lay interest upon him," in any case. Rabbi Yehudah permits the scribe. Rabbi Meir says: One who lends at interest and tells the scribe, "Write," and the witnesses, "Sign," has no portion in the One who commanded concerning interest.
Do Not Be Seen as a Creditor and Who the Interest Ban Binds
Yalkut Shimoni on Torah 350:3
לֹא תִהְיֶה לוֹ כְּנֹשֶׁה, לְעָנִי שֶׁעִמָּךְ לֹא תִהְיֶה לוֹ כְּנֹשֶׁה. לֹא תִהְיֶה לוֹ כְּנֹשֶׁה, שֶׁלֹּא תֵּרָאֶה לוֹ בְּכָל זְמַן. לֹא תְשִׂימוּן עָלָיו נֶשֶׁךְ, מַה תַּלְמוּד לוֹמַר, לְפִי שֶׁנֶּאֱמַר "אֶת כַּסְפְּךָ לֹא תִתֵּן לוֹ בְּנֶשֶׁךְ", הֲרֵי זֶה אַזְהָרָה לַמַּלְוֶה שֶׁלֹּא יַלְוֶה בְּרִבִּית. אוֹ אֵינוֹ אֶלָּא אַזְהָרָה לַלֹּוֶה, כְּשֶׁהוּא אוֹמֵר (שם, לו) "אַל תִּקַּח מֵאִתּוֹ נֶשֶׁךְ", הֲרֵי זֶה אַזְהָרָה לַלֹּוֶה, וּמַה תַּלְמוּד לוֹמַר "אֶת כַּסְפְּךָ" וְגוֹ', הֲרֵי זוֹ אַזְהָרָה לַמַּלְוֶה. אֵין לִי אֶלָּא אַזְהָרָה לַמַּלְוֶה וְלַלֹּוֶה, לֶעָרֵב וְלָעֵדִים וְלַלַּבְלָר מִנַּיִן, תַּלְמוּד לוֹמַר, לֹא תְשִׂימוּן עָלָיו נֶשֶׁךְ, מִכָּל מָקוֹם. רַבִּי יְהוּדָה מַתִּיר בַּלַּבְלָר. רַבִּי מֵאִיר אוֹמֵר, הַמַּלְוֶה בְּרִבִּית וְאוֹמֵר לַסּוֹפֵר כְּתֹב וְלָעֵדִים חֲתוֹמוּ, אֵין לוֹ חֵלֶק בְּמִי שֶׁפָּקַד עַל הָרִבִּית.