Although if someone grabs the servant of his friend and does Melachah with him he is Patur, however if he lent money to him it is forbidden because it appears like Ribis.
Although if someone lives in his friend's courtyard without his knowledge he is Patur, however if he lent money to him he must pay rent.
Abaye says if someone owes his friend a Zuz of Ribis and the market price for bushels of wheat is four for a Zuz and he gave him five bushels for the Zuz that he owes him when Beis Din takes the Ribis away from the lender they take only four bushels because the fifth bushel was given to him as a discount. (1)
Rava says that we take all five bushels from him since he received it for the Ribis that was owed to him.
Abaye says if someone owes four Zuz of Ribis to his friend and he give him a shirt for the four Zuz when Beis Din takes the Ribis away from the lender they take the four Zuz not the shirt.
Rava says that they take the shirt away from him so that people will not say that he is wearing a shirt of Ribis.
If someone is owed 12 Zuz of Ribis and the borrower allows him to live in his courtyard that is normally rented for ten Zuz for the 12 Zuz that he owes him when Beis Din takes the Ribis away from him they take away 12 Zuz. (2)
If a person rents out his courtyard and he says if you pay in advance it will cost ten Sela'im a year and if you pay per month it will cost a Sela a month it is permitted because rent is not owed until the end. (3)
If a person sells his field and he says if you pay me now it will cost a thousand Zuz and if you pay me at a later date it will cost twelve hundred Zuz it is Ribis and it is forbidden. (4)
It is permitted to sell merchandise for an inflated amount in return for allowing the buyer to pay at a later date as long as he doesn't tell him that if you pay immediately you can have it for less.
If someone sells a field and the buyer makes a partial payment if the seller tells him that when you bring me the balance of the money you will be Koneh the field from now it is Ribis and it is forbidden. (5)
R. Yehudah holds that it is permitted because he holds that when it is only a Safek if it will end up being Ribis it is permitted. (6)
If the buyer makes a partial payment and the fruit of the field is given to a third party until the buyer pays the balance of the money it is permitted. (7)
If the buyer makes a partial payment and the seller tells him you are Koneh part of the field in accordance with the amount of money that I received both the seller and the buyer may eat the fruit of the field in the interim.
If the buyer makes a partial payment and the seller tells him that when you bring the balance of the money you will be Koneh the field at that time it is permitted for the seller to eat the fruit of the field in the interim.
If the buyer makes a partial payment and the seller tells him you are Koneh the field right now and the balance that you owe is a loan it is permitted for the buyer to eat the fruit of the field in the interim.
If someone lends money on his field and he tells the lender that if I don't pay you back within three years the field shall be yours it is permitted.
If someone lends money and is given a field as a Mashkon and the says if you want to sell the field sell it to me at a specific price (below the market price) it is forbidden, but if it he tells him to sell it to him at the market price it is permitted, while R. Yehudah holds it is permitted even for below the market price.
If someone sells a house or a field and he makes a condition that when he attains the money it shall be returned to him it is forbidden, while R. Yehudah holds that it is permitted. (8)
If the buyer offers to return the house or field when the seller has the money but he doesn't make it a condition in the sale it is permitted. (9)
A BIT MORE
1. R. Elazar holds that Ribis d'Oraisa is taken back from the lender by Beis Din and even though R. Yochanan argues the Halachah is like R. Elazar.
2. The renter can't say I only agreed to live in the courtyard for 12 Zuz instead of ten because it was all profit for me but now that I am not profiting it is not worth it for me because we can tell him you accepted it for 12 Zuz and that is what you have to pay.
3. The renter is not obligated to pay the rent until the end of each month therefore the price of a Sela a month is the real price and the price of ten Sela'im a year is a discount for prepaying and it is not Ribis.
4. The money for a purchase is owed immediately and therefore the real price is a thousand Zuz and the price of twelve hundred Zuz is Ribis because he is paying extra for the right to hold on to the money for a period of time.
5. If the seller eats the fruit in the interim and the buyer eventually brings the balance of the money the fruit that the seller ate is Ribis because it is a reward for the extra time that he gave the buyer to pay the balance and if the buyer eats the fruit in the interim and he doesn't end up paying the balance and the sale is void the seller must return the money that he received and the fruit that the buyer ate is a reward for the period of time that the seller had the money and therefore it is Ribis and it is forbidden.
6. If the seller eats the fruit it is only Ribis if the buyer pays the balance and if the buyer eats the fruit it is only Ribis if he doesn't pay the balance therefore since it is a Safek it is permitted
7. If the fruit is given to a third party to hold it is permitted because if the buyer eventually pays the balance the fruit will be given to the buyer and if he doesn't end up paying the balance and the sale is void the fruit will be given to the seller.
8. Since the seller will buy it back as soon as he has the money it is a loan not a sale and the buyer is eating the fruit of the field in the interim as a reward for the right of the seller to hold on to the money in the interim and it is Ribis.
9. Since it is simply an offer from he buyer and the seller can't force him in Beis Din to give it back it is a sale not a loan and if he does give it back he is reselling it and it is not Ribis.