Bava Metzia 75B

כל ימי גריד ⁠– אחד. כל ימי רביעה ⁠– אחת. לא יאמר לו: חרוש עמי בגריד ואני אחרוש עמך ברביעה.

All the dry days during the summer, when it does not rain, are viewed as one period, meaning that if they each agreed to work one day, the dry days are viewed as though they were all exactly equal in length, despite the slight differences between them. Similarly, all the rainy days are treated as one period. But he may not say to him: Plow with me in the dry season and I will plow with you in the winter.

רבן גמליאל אומר: יש רבית מוקדמת ויש רבית מאוחרת. כיצד? נתן עיניו ללוות הימנו, והוא משלח לו ואומר: בשביל שתלוני ⁠– זו היא רבית מוקדמת. לוה הימנו והחזיר לו את מעותיו, והוא משלח לו ואומר: בשביל מעותיך שהיו בטילות אצלי ⁠– זו היא רבית מאוחרת.

Rabban Gamliel says: There is a case of pre-paid interest, and there is also a case of interest paid later, both of which are prohibited. How so? If he had hopes of borrowing money from him in the future, and he sends him money or a gift and says: I am sending you this gift in order that you will lend to me, this is pre-paid interest. Similarly, if he borrowed money from him and subsequently returned his money, and he later sends a gift to him and says: I am sending you this gift in order to repay you for your money, which was idle with me, preventing you from earning a profit from it, this is interest paid later.

רבי שמעון אומר: יש רבית דברים. לא יאמר לו ״דע כי בא איש פלוני ממקום פלוני״.

R' Shimon says: Not only is there interest consisting of payment of money or items, but there is also verbal interest. For example: the borrower may not say to the lender: You should know that so-and-so has come from such and such a place, when he is aware that this information is of significance to his creditor. Since his intention is to provide a benefit to the lender, he has effectively paid him an extra sum for the money he lent him, which constitutes interest.