Q: What are the prohibitions of ribbis (charging interest)? Who violates them?

A: The Mishna (B.M. 75b) teaches that the lender, borrower, guarantor, witnesses, and even the scribe (lawyer) violate when engaging in an interest-bearing loan. This is true even if the borrower is wealthy and willingly agrees to pay the interest (Yoreh De’ah 160:1,4). The lender violates the prohibitions, “Do not take interest from him ... Do not give him your money for interest” (Vayikra 25:35-36); the borrower violates, “Do not provide interest to your brother” (Devarim 23:20); the guarantor and witnesses violate, “Do not place interest upon him” (Shemot 22:24); and the scribe (lawyer) violates, “You shall not place a stumbling block before the blind” (Vayikra 19:14).

The Torah prohibition includes any loan of money, food or other items with a fixed-return interest (ribbis ketzutza). The Sages prohibited other transactions that include elements of interest (avak ribbis), including: floating-rate or non-guaranteed returns (ribbis she’aina ketzutza), business arrangements that contain elements of interest (ribbis derech mekach u’memkar) or resemble interest (mechzei k’ribbis), and even favors performed on account of the loan (ribbis devarim).