Yerushalmi Eruvin 8:2 ירושלמי עירובין ח׳:ב׳

MISHNAH: What is its measure? Food for two meals for everybody, food for weekday but not the Sabbath, the words of Rebbi Meïr; Rebbi Jehudah says for Sabbath but not for weekday. Both of them intended to be lenient⁴In R. Meïr’s practice, people eat more on the Sabbath because they have more time to eat and it is a festive occasion; in R. Jehudah’s practice people eat more on weekdays since they need the energy for work whereas on the Sabbath there is no exertion and, therefore, less hunger.. Rebbi Joḥanan ben Beroqa says, a loaf for a dupondius if four seah are a tetradrachma⁵A dupondius is half an obolus or one twelfth of a denarius (drachma). Therefore a dupondius is 1/₄₈ of a tetradrachma (cf. Qiddušin 1:1, Note 100.) A qab is ⅙ of a se’ah (cf. Berkhot 3:4 Note 164) or 1/24 of 4 se’ah. The Halakhah states that the baker takes ⅓ from above (which is ½ from below) for his overhead and profit. Therefore R. Joḥanan ben Beroqa requires a loaf made from ²/₃ of ½ (or ⅓) qab of flour.. Rebbi Simeon says, two thirds of a loaf if three are made from a qab⁶2/9 of a qab, 1/9 less than required by R. Joḥanan ben Beroqa.; half of this for the leprous house,⁷It is stated in Lev. 14:46 that anybody who enters a locked-down leprous house becomes impure immediately; v. 14:47 states that if somebody eats in the house even his garments become impure. This is interpreted rabbinically to mean that garments become impure if the wearer stays in the house the time needed for eating half a loaf of bread (Mishnah Nega`im 13:9). and half of this half bring impurity to a body⁸If anybody eats the volume of a quarter loaf of impure food, he may not eat sanctified food unless he purify himself in a miqweh..

HALAKHAH: Paragraph³⁶Discussion of Mishnah 2.. Rebbi Meïr says, on a weekday, when he has nothing to eat, he eats little bread. On the Sabbath, when he has something to eat, he eats a lot of bread³⁷R. Meïr states the rules for very poor people who have only a little bread for weekday meals and save all their money for a Sabbath meal.. Rebbi Jehudah says, on a weekday, when he has nothing to eat, he eats a lot of bread. On the Sabbath, when he has something to eat, he eats little bread³⁸R. Jehudah states his rule similarly for people who have no additions to the bread on weekdays and therefore eat only bread, but on the Sabbath they have meat and vegetables and therefore eat little bread..

It was stated: Their words³⁹Rebbi Joḥanan ben Beroqa and R. Simeon. Babli 82b. are close one to another. Come and see: One makes a loaf [the volume of] twelve eggs⁴⁰The Yerushalmi defines the volume of a qab as that of 24 eggs; this makes the volume of a standard egg about 89cm³. The text of the Mishnah implies that a loaf of R. Joḥanan ben Beroqa is half a qab and that of R. Simeon one third of a qab. These measures are far apart.
Since a qab is 16 quartarii, this makes the quartarius, the standard volume (reviˋit) of a ritual cup, equal to the volume of 1½ eggs. This is not found in the Babli but is accepted by the Medieval authorities (Alfasi Pesaḥim §763). In the Babli (83a) a modius is estimated as volume of 217 eggs. Based on the data collected by F. Hultsch, Griechische und römische Metrologie², Berlin 1882, the modius in question is either the Egyptian provincial of 11.8 1 or the Syrian large modius of 17.5 l. The Yerushalmi quartarius is the Roman measure (Mishnah Kelim 17:11) of 133.2 cm³, whereas 1½ Babli eggs, which according to Rav Nissim (ad 82b) define the Gaonic quartarius, are either 82 or 121 cm³., the other makes a loaf of eight, and you are saying so? Rav Huna said, deduct a third for expenses⁴¹As explained in Note 5, this makes the difference between the loaf sizes only 1/9 qab.. ⁴²Peah 8:6, Notes 77–78. Rebbi Yose ben Rebbi Abun gave to the bakers according to the statement of Rav Huna, but only for these measures⁴³For larger quantities, the price to be paid to miller and baker may be less and can be freely negotiated without being unfair to the baker..