Keilim, Chapter 17, Mishnah 4. This chapter is built around the measures that determine when a vessel has stopped being a vessel. A wooden container that develops a hole is judged by the pomegranate: once the opening is wide enough for a pomegranate to pass through, the container is no longer considered fit for use, and from that point on it is tahor and can no longer receive tumah. Our mishnah now fills in the details of that measure, and then turns to vessels that are simply too small for pomegranates to be a relevant standard at all.
What Exactly Is the Pomegranate Measure?
The mishnah opens: "Harimonim she'amru shelosha ahuzin zeh bazeh" - the pomegranates spoken of earlier in the chapter mean three pomegranates held together, one pressed against the next. The measure is not the width of a single fruit lying by itself. We picture three pomegranates squeezed against one another, and we ask whether one of them would drop out through the hole in the vessel. If it would, the vessel is broken and tahor.
Why does this make the measure larger rather than smaller? Because pomegranates pressed against each other exert pressure on one another, and each one to some degree braces and steadies its neighbors in place. A hole through which a single loose pomegranate would slip is therefore not enough; when three are wedged together, none of them will fall through such an opening. The hole must be wider than that before we call the vessel broken. This is the shiur that Mishnah Aleph had in mind.
Vessels That Are Carried and Shaken
"Rabban Shimon ben Gamliel omer, benafah uvichvarah kedei sheyitla veyelech" - Rabban Shimon ben Gamliel teaches that certain vessels become tahor with a hole smaller than the measure just described. In the case of a nafah and a kevarah, a sifter and a sieve, we measure by picking the utensil up and walking with it. If, while it is being carried, the jostling would cause one of the three pressed pomegranates to fall out, the utensil is considered broken. The motion supplies pressure that a stationary vessel does not have, so a pomegranate will escape through an opening narrower than the one required when the vessel sits still.
"Uvekufah kedei sheyafshil le'ahorav" - and in the case of a large basket, the measure is what would happen if a person slings it over his shoulder onto his back. Here too, if the swinging and shifting of the basket would dislodge one of the three pomegranates, the basket is tahor, even though the hole is smaller than the shiur given at the start of the mishnah. These are utensils whose ordinary use involves movement, so their fitness is judged in movement.
Vessels Too Small for Pomegranates
Attention now shifts to wooden utensils of such modest size that a pomegranate could never sit inside them to begin with. Since the fruit offers no workable yardstick here, the question becomes: at what stage of damage do we declare that such a utensil has ceased to function as a container, so that it sheds its status and becomes tahor?
"Ushe'ar kol hakelim she'einan yecholin lekabel rimonim" - the remaining vessels, the ones too small to contain pomegranates. Three examples follow. "Kegon harova" is a measuring utensil with a capacity of a quarter kav, equivalent to six eggs. "Vahatzi harova" is half that amount, the volume of three eggs. "Hakinonim haketanim" are little sifting baskets. Concerning all three, "shi'uran beruban": the standard is the majority of the utensil. Nothing less will do; the damage has to remove the larger portion, whether that is most of its height or most of its floor, before we say a utensil is gone and tumah no longer attaches. So rules the first tanna, and the mishnah records it as "divrei Rebbi Meir".
Rebbi Shimon: It Depends Where the Break Is
A second tanna disagrees, and his standard depends on where the vessel broke.
"Rebbi Shimon omer, bezeitim" - for Rebbi Shimon, the yardstick for these little utensils is the olive rather than the majority. Should the floor of the utensil have an opening large enough for an olive to slip through, that alone renders it tahor, and it makes no difference that the gap falls far short of most of the base.
"Nifretzu, shi'uran bezeitim" - if they broke open in the wall low down, near the bottom, the measure is likewise the olive. Once an olive would fall out through that breach, the utensil is no longer fit and is tahor.
"Nigmemu, shi'uran bemah shehen" - but if they were chipped or broken away at the top, the measure is whatever remains. As long as there is still some form of wall left, so that the utensil can hold even a small amount, it remains a utensil and can still become tamei. The logic is straightforward: damage at the rim does not really impair the rest of the vessel's ability to contain. If it can still hold something, it is still a container, still a utensil, and still susceptible to tumah.
So this mishnah gives us two scales side by side. For a vessel large enough for pomegranates, the shiur is the pomegranate, understood as three pressed together, and adjusted for utensils whose normal use is in motion. For a vessel too small for pomegranates, the sages debate between the greater part of the vessel and the olive, with the olive applying to breaks at or near the bottom, while a chipped rim leaves the vessel fully intact in the eyes of halachah as long as it can still hold anything at all.