Keilim, Chapter 17, Mishnah 5. The preceding mishnayot fixed one of the most familiar measures in all of Masechet Keilim: a perforation as wide as a pomegranate. Once a vessel has been breached to that extent, it no longer functions as a keli, its standing as a vessel falls away, and from then on it is tahor. Our mishnah presses the natural question that follows: when the chachamim spoke of "a pomegranate," which pomegranate was meant? Pomegranates, after all, grow in a wide range of sizes.
The mishnah answers: "harimon she'amru, lo katan velo gadol, ela beinoni." The pomegranate that is spoken of again and again in these halachot is neither a small one nor an unusually large one, but a medium sized pomegranate. That is the standard by which we measure the hole in a vessel.
So what were the pomegranates of Baddan mentioned for?
Having settled that the measurement uses an average pomegranate, the mishnah raises a difficulty: "velamah huzkeru rimonei Baddan?" Baddan was a place in Eretz Yisrael that was famous for its exceptionally large pomegranates, and the chachamim do mention "the pomegranates of Baddan" in connection with a halachah. If our measurement is taken from an ordinary medium pomegranate, for which law were those large Baddan pomegranates singled out?
The answer given here is: "sheyihyu mekadshin kol shehen," that they render a mixture forbidden no matter how small a quantity of them is present. Consider a pomegranate that is itself forbidden, for example a pomegranate that grew during a tree's first three years and is therefore orlah, or a pomegranate that grew in a vineyard and became kil'ei hakerem. If a single forbidden pomegranate of this kind falls in among permitted pomegranates and we can no longer identify which is which, the entire mixture is forbidden, even if it fell into a thousand permitted ones.
This severity, says the mishnah, applies specifically to the pomegranates of Baddan. With ordinary pomegranates the usual rules of bittul, nullification, would take effect, and the mixture would be permitted. But a Baddan pomegranate was a prized and valuable item, and the principle is that a davar chashuv, an item of significance, is not subject to nullification. It keeps its identity in the mixture and forbids the whole. "Divrei Rabbi Meir," this entire explanation is the view of Rabbi Meir.
Three further opinions
The second view belongs to Rabbi Yochanan ben Nuri, who states the reason as "lesha'er bahen et hakelim." In his opinion the fruit of Baddan was singled out for exactly one purpose: it supplies the standard for gauging a breach in a vessel. He thus rejects the assumption of the mishnah's opening line. As he understands it, the perforation is not assessed against an average pomegranate; it is assessed against the oversized pomegranates of Baddan, and those are the very pomegranates that the earlier mishnayot had in view from the start.
"Rabbi Akiva omer: lekach ulechach huzkeru, lesha'er bahen et hakelim veyihyu mekadshin kol shehen." Rabbi Akiva combines both approaches. The pomegranates of Baddan were mentioned for both purposes: to serve as the measure for holes in vessels, and also for the law that they forbid a mixture in any amount whatsoever.
Then comes a fourth position. "Amar Rabbi Yose" (some texts of the mishnah attribute the ruling to Rabbi Yehudah): "lo huzkeru rimonei Baddan vachatzirei Geva ela sheyihyu mit'asrin vadai bechol makom." Neither of the two laws discussed so far is the reason Baddan's pomegranates were named. They appear, alongside the leeks of a locale called Geva, for one halachah alone, and it belongs to the laws of ma'aser: from these two products the tithe must be taken as ma'aser of certainty, in every place.
Ma'aser vadai and demai
To appreciate this, we need the concept of demai. When a person buys produce from an am ha'aretz, someone who is not knowledgeable in halachah and not trusted in these matters, the buyer must separate ma'aser himself, since he assumes the seller did not. Yet in truth he is dealing with a safek, a doubt: perhaps we are being overly suspicious of the am ha'aretz, and perhaps he did in fact tithe his produce. For that reason the ma'aser separated in such a case is called demai, ma'aser of doubt, and it carries the halachic consequences of an uncertain status.
Baddan's pomegranates and Geva's leeks form the exception to that rule. Those crops came from kutim, a population that had embraced Judaism yet did not observe what the Torah requires, and it was common knowledge that they left their produce untithed. Consequently, one who purchases either of these two items and tithes it is taking ma'aser vadai, tithe of certainty, rather than demai. On this view, that halachah is the entire reason the chachamim ever named the produce of these two places, and the ruling extends to nothing beyond those two items: the pomegranates of Baddan and the leeks of Geva.
Our mishnah thus leaves us with a small dispute of wide reach. The measurement of a pomegranate sized hole, which determines whether a vessel remains a keli at all, depends on identifying which pomegranate the chachamim meant, and the very same famous fruit stands at the center of questions of nullification and of tithing as well.