The Mishna on today’s daf teaches a basic principle regarding blessings over food: in a case where primary and secondary foods are eaten together, the blessing on the primary food exempts the secondary from a blessing. Somewhat surprisingly, according to the Mishna, even bread, the most significant food as far as blessings are concerned, can be considered secondary to another food.
In searching for a case where bread would be considered secondary, the Gemara brings the following:
Rav Aḥa, son of Rav Avira, said that Rav Ashi said: This halakha was taught with regard to those who eat fruits of Genosar, which are extremely sweet and which would be eaten along with salted foods in order to temper this sweetness. They would eat bread along with those salted foods, which was therefore considered secondary.
This teaching led the Gemara to wax hyperbolic about the qualities of the fruits of Genosar:
Rabbi Abbahu ate fruits of Genosar until the sweet, lush fruits made his skin so slippery that a fly would slip from his forehead. And Rav Ami and Rav Asi would eat them until their hair fell out. Rabbi Shimon ben Laḳish would eat them until he became confused. And then Rabbi Yoḥanan would tell the household of the Nasi about his condition and Rabbi Yehuda Nesia would send the authorities after him and they would take him to his house.
Genosar is the name of a beautiful valley that stretches along the western shore of the Sea of Galilee, north of Tiberius. Josephus describes the area as follows: “Its nature is wonderful as well as its beauty; its soil is so fruitful that all sorts of trees can grow upon it, and the inhabitants accordingly plant all sorts of trees there; for the temper of the air is so well mixed, that it agrees very well with those several sorts, particularly walnuts, which require the coldest air, flourish there in vast plenty; there are palm trees also, which grow best in hot air; fig trees also and olives grow near them, which yet require an air that is more temperate. It supplies men with the principal fruits, with grapes and figs continually during ten months of the year and the rest of the fruits as they become ripe together through the whole year; for besides the good temperature of the air, it is also watered from a most fertile fountain” (Wars of the Jews, Book III, 10:8).