EXOD744 Do not be a party to any loan that involves the charging of interest. We are forbidden to play any role in such a loan. Thus, if interest is involved, we cannot serve as guarantors or witnesses or write the legal document (the I.O.U.) that proves the loan’s existence. Having chosen Israel as His people, Hashem desires our survival and well-being. Therefore, He removes from us a stumbling block and commands that no Jew may devour his fellow Jew’s money or property little by little in a way that the borrower does not feel it until it is too late, which is the way of interest charges on loans.