Following on the heels of the discussion on yesterday’s daf regarding the possibility of ribit (forbidden interest) even in cases of purchases that are paid for in advance, the Gemara on our daf tells of a similar ruling.
Once Rav Kahana was sitting in the back of Rav’s study hall and he heard that Rav who was lecturing to the students said kari, kari (“gourds, gourds”), but he was not able to follow the context in which Rav made that reference. After the lecture he asked the students to tell him what issue Rav was discussing, and they told him that he was teaching about a case where someone selling gourds offered a better deal to a purchaser who was willing to pay in advance. Specifically, he taught about a case where someone offers a zuz to a gardener in exchange for gourds at a time when the market rate is ten small gourds for a zuz. If the gardener offers to supply large ones at a later date in exchange for the zuz, that offer can only be accepted if the gardener has large ones in hand at the time of the agreement. If, however, he does not have them in hand, then he effectively is taking a loan from the purchaser and is offering to pay back more than was borrowed – a clear case of ribit. The Gemara explains that Rav’s ruling adds to our knowledge that even in a case where the same objects are given, whether they are large or small (since the gourds get larger on their own), still it would be considered a case of ribit.
Kari (or kera) are identified as bottle gourds – Lagenaria vulgaris – a summer plant. These plants usually grow on the ground, although occasionally their vines are hung on trees. The fruit of the young gourd is usually eaten cooked while its seeds are commonly eaten as a snack or dessert.