After 2 failed attempts at understanding the case in the mishna where interest is forbidden by rabbinic decree, Rava brings an explanation according to Rabbi Oshaya’s braita and according to Rabii Yannai’s opnion – that one can turn a loan of money into a loan of produce and not be worried that prices will fluctuate if the borrower has the item in his possession. However, if he does not, then it appears like interest since the price may rise and in the end he will receive a higher value. Rav disagrees with Rabbi Yannai adn thinks that one cannot turn a loan for one item inot the value of the item to then transfer it into money or a different item (like wheat for wine – as in the braita of Rabbi Yoshaya). Two explanatinos are given as to how he can go against the braita of Rabbi Oshaya. One of them is that it follows the unique opinion of Rabbi Yehuda that a transaction where there is potential for interest but it is not clear that there will be an interest payment (maybe prices will stay the same or go down and the lender will not receive more value), is allowed. Rabba and Rav Yosef distinguish between and loan and a sale and allow in a sale to pay up front and only receive produce at a later date even if the seller doesn’t have them yet in his possession. Rav Nachman teaches that any case of getting payment for waiting is considered interest and a case is brought to illustrate.