סימן סה סעיף כז

יִשְֹרָאֵל שֶׁהִלְוָה לְעוֹבֵד כּוֹכָבִים עַל מַשְׁכּוֹן בְּרִבִּית כָּךְ וְכָךְ לְחֹדֶשׁ, וְאַחַר כָּךְ בָּא הַיִשְֹרָאֵל לַחֲבֵרוֹ שֶׁהוּא יַלְוֵה לוֹ אֶת הַמָּעוֹת עַל מַשְׁכּוֹן זֶה, וְשֶׁהוּא יִטּוֹל אֶת הָרִבִּית שֶׁתַּעֲלֶה מֵהַיּוֹם עַד הַפֵּרָעוֹן, מֻתָּר. אֲבָל אִם הַיִשְֹרָאֵל הָרִאשׁוֹן כְּבָר זָקַף אֶת הַקֶּרֶן עִם הָרִבִּית לְכָל זְמַן הַהַלְוָאָה הֲרֵי הַכֹּל הִיא כְּקֶרֶן שֶׁל יִשְֹרָאֵל, וְאָסוּר לִלְוֹת עַל מַשְׁכּוֹן זֶה מִיִשְֹרָאֵל חֲבֵרוֹ בְּרִבִּית, דַּהֲוֵי כְּאִלּוּ נָתַן אֶת הָרִבִּית מִכִּיסוֹ.

If a Jew lent [money] to a gentile on collateral for a certain rate of interest per month, and then the Jew comes to his fellow [Jew] [and asks] that he lend him the [same amount of] money [originally lent to the gentile] for this collateral,⁵²I.e. the collateral originally given by the gentile. and that he should collect the interest [owed by the gentile] that will accumulate from now until the payment [of the loan], it is permitted.⁵³Since the interest is not yet in the Jew’s possession, it is, in effect, the gentile paying the ribis to the fellow Jew. However, if the first Jew⁵⁴The one who made the original loan to the gentile. has already set the [total amount of] the principal and the interest for the entire duration of the loan,⁵⁵I.e. the total obligation of the gentile is set and no longer depends on the payment date. [then], the whole [amount] is considered as principal belonging to the Jew and it is prohibited to borrow with this collateral from his fellow Jew for interest, because it is as if he paid the ribis from his own pocket.⁵⁶Since the total payment has been determined, the first Jew, who has the gentile’s collateral, is considered to be in possession of the payment of his loan. Thus, despite that the actual payment of interest is handed over from the gentile to the second Jew, nevertheless, it is as if the money is coming from the pocket of the first Jew and is, therefore, prohibited.

תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)