Demai, Chapter Two, Mishnah 5. In the previous mishnah we learned about sellers who normally sell in a coarse measure, that is, in large quantities, who were permitted to sell demai on the assumption that it is the buyer who will be required to separate the tithes of demai.
The view of Rabbi Meir:
In our mishnah Rabbi Meir teaches that whether we are dealing with a coarse measure or a fine measure is determined by what is customary for that type of produce, and not by the particular case before us:
"Es shedarko limaddedo b'gassah, medado b'dakah - tipol dakah l'gassah" - produce that is normally measured in a large quantity, and in this instance it happened to be measured in a small quantity, follows the rule of the coarse measure, which is what is customary for produce of this type. Therefore the seller is exempt from separating the tithes of demai.
"Es shedarko limaddedo b'dakah, u'medado b'gassah - tipol gassah l'dakah" - produce that is normally measured in a small quantity, whose seller is obligated to separate the tithes of demai, and in this instance it happened to be sold in a large quantity, here too we follow what is customary, namely the fine measure, and so he is obligated in demai, even though in this case it was sold in a coarse measure.
It emerges according to Rabbi Meir that we follow the fixed norm for that type of produce, and not the particular case before us.
What is a coarse measure?
"Bayavesh - sheloshah kabin" - when measuring a dry item, three kabin.
"U'valach - dinar" - when measuring a liquid item, the measuring is done by weight, the amount of a dinar.
Once the quantity reaches this amount, it is considered a coarse measure, and the seller is exempt from demai.
The view of Rabbi Yosei:
Rabbi Yosei says: "Salei te'einim v'salei anavim v'kupos shel yarak, kol zman shehu mochran achsarah - patur" - baskets of figs and baskets of grapes and crates full of vegetables, as long as the seller sells them by estimate and is not particular about the exact quantity, he is exempt from demai. The very fact that he is not particular about the quantity shows that this is a type of produce generally sold in large quantities, and therefore it is considered a coarse measure, and he is exempt from separating demai before the sale.
In summary: in this mishnah we learned the view of Rabbi Meir, that the obligation in demai is determined by the produce's usual manner: if it is normally sold in a coarse measure, he is exempt even when it was measured in a fine measure, and if it is normally sold in a fine measure, he is obligated even when it was measured in a coarse measure. We clarified the amount that constitutes a coarse measure: for a dry item, three kabin, and for a liquid, a dinar. Finally we learned the words of Rabbi Yosei, that baskets of figs and grapes and crates of vegetables that are sold by estimate, without being particular about the quantity, are considered a coarse measure, and one who sells them is exempt from demai.