Before us is Mishnah 5 in chapter 9 of Maseches Terumos. Here is a piece of advice, especially for anyone who has just finished learning Mishnah 4: it is better to skip this Mishnah, to learn Mishnah 6 first, and only then to come back to it.
The Mishnah deals with a case where a person planted some of the rows of his field with Terumah seeds, while other rows were planted with ordinary chullin seeds, and in the end he lost track of which rows were which. What is the status of the entire field: does it become permitted or forbidden, that is, is it subject to the restrictions discussed in the previous Mishnah and in the one that follows.
The words of the Mishnah:
"Me'ah laginah shel Terumah v'achas shel chullin" - there were a hundred garden beds in the garden that were planted with Terumah seeds, and even just one single bed that was planted with chullin seeds.
"Kulan mutaros b'davar shezar'o kaleh" - we are lenient and say that the entire field becomes permitted, provided that we are dealing with the kinds of seeds that disintegrate in the ground.
In the previous Mishnah we learned "gidulei Terumah Terumah": one who plants wheat of Terumah, whatever grows from it is Terumah, with all the restrictions discussed in the earlier Mishnayos in that same strange scenario. Even so, when he had in his hand seeds of which some were Terumah and some were chullin and he lost track of which were which, all the wheat in the field becomes permitted, meaning that the rabbinic ruling of "gidulei Terumah Terumah" does not take effect. This leniency was stated specifically regarding "davar shezar'o kaleh" - the kinds of seeds that disintegrate in the ground.
"Aval b'davar she'ein zar'o kaleh":
When we are dealing with the kinds of things whose seed does not rot away, such as onions: a person planted a hundred and one rows of onions in his field, a hundred of them chullin onions and only one of them Terumah onions, and he lost track of which rows were which - "afilu me'ah shel chullin v'achas shel Terumah, kulan asuros". All the onions in the field are restricted and treated as Terumah, as was discussed in the first three Mishnayos of the chapter, and the rabbinic ruling continues to apply. And this is so even though we are dealing with an extreme minority of one against a hundred, and it should be remembered that in mixtures of chullin and Terumah, once the ratio reaches a hundred of chullin against one of Terumah the mixture becomes permitted - and here it does not.
The question begs to be asked: why are we not lenient here? Why are the onions not nullified, and why are they not nullified even at a ratio of a hundred to one?
An introduction to the laws of nullification:
The usual rule in nullification is that a simple majority is enough. When there is imparting of taste - and that is not the case before us - sixty times as much is sometimes required. But whatever the details of the halachos of nullification in mixtures may be, where the forbidden item loses its status relative to the majority and the entire mixture takes on the status of being permitted, there are exceptions.
The Sages established three categories of exceptions, in which the item is not nullified regardless of the ratios:
Items that are significant in their own right - according to the judgment of the Sages.
Items whose effect on the mixture is too significant to be ignored - despite the ratios.
Davar sheyesh lo matirin - things for which there is a way that they will become permitted. Since they will be able to become permitted later on, the Sages did not permit them in a mixture already now. This category is somewhat beyond the scope of our discussion.
The first category - things that are inherently significant:
Beryah - a complete unit of a forbidden item: a whole fly, a whole gid hanasheh, or a limb taken from a living animal. A complete unit of a prohibition is never nullified in a mixture, and therefore a fly that fell into a loaf renders the entire loaf forbidden until it is removed. This is not because the fly imparts taste, but because the fly itself is not nullified in a mixture.
Chatichah hare'uyah lehiskabed - a piece of food significant enough in its own right that one could serve it to a guest, such as a whole steak. Its inherent importance prevents it from being nullified in a mixture.
Davar shebeminyan - the sorts of items that are counted out one by one when purchased, the classic example being eggs.
The second category - things whose effect is noticeable:
Spices - if a hot pepper falls into the cholent, even though the meat and potatoes outnumber the pepper a hundred times over, and even a thousand times over, since the taste of the pepper is still detectable when you taste the food, you cannot say that it has disappeared. It is calling out "Here I am, here I am," and it is not nullified.
Ma'amid (a catalyst) - we have already encountered this several times in our tractate. The classic example is the enzyme used to produce cheese: you add the enzyme to milk, the milk curdles, and cheese results. Even if the enzyme makes up one part in a thousand of the mixture, since you are no longer looking at milk but at cheese, it is obvious that an enzyme was introduced here. The same is true of yeast and bread: you cannot deny that the yeast had an effect, for the bread rose.
The third category - davar sheyesh lo matirin:
Items that will become permitted at a later point, so there is no need to eat them now. This category is more technical than the previous ones. For example: someone had an egg that may have been laid on Yom Tov, and he cooked it into an omelet, and afterward remembered that one of the eggs in the mixture may have been laid on Yom Tov. That egg is forbidden as muktzeh, and he may not eat it until after Yom Tov, but after Yom Tov it becomes permitted. Even though it is mixed in and is the minority, it is not nullified, because it has something that will permit it: if he waits until after Yom Tov, he will be able to eat the egg mixture. That is enough for our purposes at this stage.
For some reason we say that the row of onions in our Mishnah is likewise too significant to be nullified, even at a ratio of a hundred to one - a ratio that was effective even in an ordinary mixture of Terumah of the same species, where we said that there is no dimua beyond a ratio of a hundred to one, whereas here there is a problem. This is puzzling, since the list of categories we have enumerated does not seem to have anything to do with a row of onions. Why, then, are the onions not nullified?
The Bartenura writes: "lefi she'ein hakarka olah be'achas ume'ah" - because something attached to the ground is not nullified in one hundred and one. There are two basic ways to understand his words:
Things attached to the ground are inherently too significant to be nullified, and they belong on the list of items that are not nullified.
As the Rambam holds: since the item is attached to the ground and stands in its own place, separate from the others, there is no mixture here at all. Nullification requires that the forbidden and the permitted be mixed together, and as long as the item is attached to the ground you cannot say that it is mixed with anything else.
Either way, when it comes to produce whose seed does not disintegrate, what comes up out of the ground is limited, and there is no nullification as long as it remains attached to the ground.
"Kol deparish merubah parish" versus "kol kavua":
And if you ask: once several onions have been uprooted from the ground, why are those onions not permitted now? After all, the usual rule is that when something is taken out of a mixture and separates from it, we say "kol deparish merubah parish" - whatever separates, separates from the majority - and we assume that it came from the majority. Here a hundred out of the hundred and one rows are permitted, so seemingly we should be able to assume that the questionable onion came from the majority and is permitted.
The classic case in the Gemara is a person who finds a piece of meat in the town square. Why anyone would want to eat raw meat picked up in the town square is hard to say, but if that is what he wants, the question is whether we may assume the meat is kosher. If the town had ten butchers, nine of them kosher and one selling non-kosher meat, we may assume the meat came from one of the kosher butchers, since the kosher ones are the majority, and "kol deparish meruba parish" - anything that separates from a group is assumed to have come from the majority. We are speaking, of course, about a piece of meat that is not significant enough to be served to a guest - not a whole steak, but meatballs and the like.
Although this rule is correct, it applies only when, at the moment the doubt arose, at the point when the status of the meat was unclear, the meat was no longer in the original place of the prohibition.
For example: a woman comes home from the market and tells her husband that she bought meatballs. He asks her, "Did you buy from the kosher butcher or from the butcher who is not kosher?" and she answers, "I don't know." If there is a non-kosher butcher in town, the halachah is that the meatballs are forbidden, and we can no longer say "kol deparish meruba parish" - that it came from the majority.
And here one scratches one's head and asks: why? This is a question people puzzle over for years. The answer is that at the moment the question arose, at the moment the woman took the piece of meat, that piece was still in its place - either she received it from a kosher butcher or from a butcher who is not kosher, and statistics cannot be applied here. At the moment she took it, it was either yes or no, whereas "kol deparish meruba parish" - the rule of following the majority - was stated only where we are relying on probability.
With meat found in the town square, the doubt was purely statistical: the probability is that the meat came from a kosher butcher, and had another hundred pieces been found there, statistically ten of them would have come from the non-kosher shop and ninety from the kosher one. But the meatball the woman brought home - if the case were repeated a hundred times, all hundred would be non-kosher, since the source it came from is non-kosher. Once the doubt arose in its place, in a place where the item is either kosher or disqualified, we say "kol kavua" - anything fixed in its place: since the question arose in its fixed place, in a setting where probabilities do not apply, it is "kemechetzah al mechetzah damya" - considered a fifty-fifty split, and we cannot be lenient.
And from here back to the onions: one who uproots a row of onions from the ground either uprooted a permitted row or uprooted a forbidden row, and this is a case of kavua, since the doubt arose while the item was still in its place, parallel to the woman buying meatballs from the butcher who is not kosher. For that reason we do not apply "kol deparish meruba parish" - following the majority - here, but rather "kavua kemechetzah al mechetzah" - a fixed item counts as fifty-fifty, and therefore the onions remain forbidden even after they are harvested. Here the Mishnah concludes.
If you are left scratching your head over something said here - a great deal was covered, and it is the kind of material that people wrestle with for many years. You can listen to the lesson again, review and investigate, and certainly ask as many questions as you need; questions are always welcome. The rule of "kol deparish" versus "kol kavua" is genuinely a thorny and complex subject.