If one takes interest forbidden by the Torah, according to rabbi Elazar, the court can force him to return it. Various cases are brought in which the interest was different than they had agreed upon. In each case, does the lender need to return what was agreed upon or what he actually received? The mishna distinguishes between rentals and sales in terms of agreeing to a higher price if the buyer/renter pays at a later date. In rental contracts it is allowed because generally rentals are paid at the end so there is no benefit to paying at the end as that is what is expected. This is different from a sale where money is generally paid from the beginning. Some rabbis each try to explain cases from their business practices explaining how they justify that they charge a higher rate to those who pay at a later date. If a buyer pays only part of the money and says he will pay the rest later, what happens in the interim period? Can either side eat the produce? A braita is brought which explains that there are 4 possible options – depending on what the wording of the agreement was.