Dealing with Forbidden Goods
4. Even if, at the outset, no interest was stipulated, and the borrower
voluntarily adds to the amount he owes when he repays the debt without
referring to the increase as interest, this, too, is forbidden.
5. Even when the borrower explicitly states that he is giving the increase
as a present, the lender is forbidden to accept it from him. However, under
such circumstances, should the lender have already accepted the interest he
took, if the borrower foregoes repayment, the lender is not obligated to
return the money.
6. It is also forbidden to pay interest before or after taking a loan. For
example, Reuven wanted to borrow money from Shimeon. Therefore, he sent him
a present beforehand, explicitly telling him that the present was being
given so that he would grant him the loan. Alternatively, he sent him a
very large present with the obvious implication that he was doing so in
order to receive a loan.
The above exemplifies interest given before a loan. An example of interest
being given after a loan is a person who took a loan, repaid it, and,
afterwards, sent the lender a present in appreciation.