Menachos Chapter 7, Mishnah 1. From here on, the Mishnah turns to discuss the measuring vessels in the Beis HaMikdash and their technical details. Our Mishnah deals with the measuring vessels themselves: "Shtei midos shel yaveish hayu ba'Mikdash" - for measuring dry goods, that is, for measuring fine flour, there were two sizes of vessels: the issaron and the half-issaron. The issaron is the primary vessel, and alongside it there is the half-issaron. In the next Mishnah we will deal with the measuring of liquids, for oil and the like.
An issaron, as has been mentioned several times, means a tenth - a tenth of an eifah, which is 43.2 egg-volumes. One can picture this as roughly the volume of a gallon. This is the quantity of fine flour that goes into each and every minchah. The half-issaron measure was used for the chavitin of the Kohen Gadol alone, as will be explained below - a special, one-of-a-kind matter, while all the other menachos were measured with the issaron measure.
The View of Rabbi Meir - Three Measures:
According to the Tanna Kamma, the issaron measure is the vessel which, when filled to its rim and leveled off across the top, yields exactly one issaron. Rabbi Meir says that there were three measuring vessels there: an issaron, an issaron, and a half-issaron.
How can there be two measures of an issaron?
The idea is that in measuring things there are two possibilities: measuring with a leveled vessel, or measuring with a heaped vessel. Certainly the issaron measure, which is 43.2 egg-volumes, requires exactly 43.2 egg-volumes of fine flour. But in Rabbi Meir's view it is fitting, both in terms of visual appearance and for reasons one might call psychological, that the measuring vessel be heaped and protruding above the rim, and this is what we learn should be done. Therefore, the regular issaron measuring vessel actually holds less than a full issaron, since the missing remainder is made up by the heap above the rim of the vessel - and this is how it is supposed to look. In the end the correct volume is obtained, and this is the regular vessel that is used.
Alongside it there is an additional issaron, a larger measuring vessel, which if it were filled with water would hold a full issaron, meaning that its volume is a precise issaron. This vessel was designated for a specific use - the making of the chavitin of the Kohen Gadol. There they take the entire issaron that he brings and divide it into two halves, and therefore it cannot be heaped and protruding above the rim, lest it spill onto the floor. It emerges that according to Rabbi Meir the issaron used for all the menachos was slightly smaller than the issaron according to the Tanna Kamma, for Rabbi Meir requires a heap on top, while the Tanna Kamma holds that this is not necessary.
"Issaron mah hayah m'shameish?":
The Mishnah goes on to explain: "She'bo hayah modeid l'chol ha'menachos" - this was the measuring vessel used for all the menachos. And it continues: "Lo hayah modeid lo b'shel sheloshah la'par v'lo b'shel shenayim la'ayil, ela modeid esronos". This refers to the minchas nesachim: the minchah that accompanies the korban varies according to the animal.
A bull: its minchah is three esronos.
A ram: its minchah is two esronos.
The Mishnah teaches that there was no measuring vessel in the Mikdash with a volume of three esronos or a volume of two esronos, but only a vessel of a single issaron, with which they measured two or three times in order to reach the quantity of fine flour required for the minchah appropriate to those animals.
"V'chatzi issaron mah hayah m'shameish?":
"Shebo hayah moded chavitei Kohen Gadol, machatzah baboker u'machatzah bein ha'arbayim" - the half-issaron was used for measuring the chavitin (griddle-cakes) of the Kohen Gadol: half in the morning and half in the afternoon. It is worth recalling what we learned in chapter 4, mishnah 5: "Chavitei Kohen Gadol lo hayu ba'os chatza'in" - the Kohen Gadol cannot bring half an issaron of fine flour; he must bring the full amount, a complete issaron. It is only the burning on the altar that is done in two halves.
The dispute among the Rishonim as to how the division works:
The Raavad and most Rishonim: Two separate batches are made - six loaves in the morning and six in the afternoon, twelve in all. According to this, one takes the entire issaron of fine flour, divides it into two half-issaron portions, cooks one half in the morning and bakes the second half in the afternoon.
The Rambam: Twelve loaves are made, and half of each one is offered in the morning and half in the afternoon. According to his approach, dividing the flour into two half-measures is part of the process of preparation: six loaves are made from each half, and afterward each of the twelve loaves is cut in two, with half offered in the morning and half in the afternoon. This approach seems more complicated in light of the wording of the mishnah, and most Rishonim do not learn it this way.
The Bartenura: He learns like the Rambam, that the two half-measures are indeed used to produce the full quantity of the chavitin of the Kohen Gadol.
To summarize: In this mishnah we learned about the two dry measures that were in the Temple - the issaron and the half-issaron; about Rabbi Meir's view that there were three measures there, and about the distinction between a leveled vessel and a heaped vessel; about the fact that the issaron was used for all the menachos, and that even for the menachos of the bull and the ram they measured with it two or three times; and about the half-issaron that was used for the chavitin of the Kohen Gadol, half in the morning and half in the afternoon, along with the dispute among the Rishonim as to how they are divided.
In the next mishnah we will deal with the liquid measures - the measuring vessels for oil and for liquids in the Temple.