I think the logic is that if you grab too much, in the end you’ll lose everything, including what you could have grabbed. For example, if a person wants to clear many books from his desk to his bookcase, he can clear them one by one or all at once, but if he tries to move them all at once, they’ll probably fall from his hands while he walks from the desk to the bookcase, and then in the end he loses more time than if he had moved them one by one.

That’s the explanation for the common Hebrew saying. But here it refers to an interpretive / midrashic rule.

I don’t know anything about the topic, but the first result on the Dicta site for searching “if you grasp too much” brings a passage in Yoma 80 that infers from a verse that food impurity has a measure of an egg-bulk (“food from food”), and in deciding which egg — a regular one (a chicken egg) or a large one (the bar yokhani bird) — it says: “if you grasp the lesser, you have grasped it,” meaning a chicken egg. And that is a stringency, since already from the measure of a chicken egg the food imparts impurity. Seemingly, that’s not the point of “there’s no proof,” and also not something like “we compare toward stringency,” but rather an interpretive issue.

On the contrary, that’s exactly what it says there. The Torah renders foods impure, and now the question is at what measure. You take the result in the stringent direction because that is the minimum novelty. For positive commandments it might come out lenient, because that is the minimum novelty.

But why present it that way in two stages? (It reminds me of what you brought as a practical difference for the conceptual inquiry in tort law.) Before the verse, everything is pure; the verse comes to render something impure, and we only know for certain that it renders a bar-yokhani-sized amount impure, and we have no proof for less than that.

I agree that one could have said that, but since my understanding is that this rule means choosing the minimal novelty, apparently here too the intent is the minimal novelty in that way. One should remember that this rule is not presented as a law given to Moses at Sinai or as some kind of tradition. It is probably the product of reasoning.

Indeed, I see in Hullin 137 that they learn that the measure of the first shearing given to the priest has to be enough for a priestly garment, and they conclude: like a small sash, not like a large robe, because “if you grasp the lesser, you have grasped it.” And with regard to the object of the obligation — namely the giver — that comes out leniently in a positive commandment (maybe monetary).
I understand from your words that even if this were a prohibition, “do not withhold your first shearing from the priest” according to the measure of a priestly garment, it would still be a sash, because were it not for the law of a measure, we would say that even one strand of wool exempts the shearing.
It seems that this also explains another small point I saw there in passing: regarding the size of the flock that becomes obligated in “the first shearing of your flock,” there is a dispute whether the minimum flock is 2 or 5, and they did not say there “if you grasp the lesser (2), you have grasped it.” Presumably this could be explained in other ways too (for example, that here there are positive indications rather than an absence), but maybe the explanation is that here there aren’t two stages but only one stage, because we have no prior understanding at all of what size flock is called “flock,” and therefore it is not relevant to preserve the first stage as much as possible and then grasp the lesser in the second stage. Does that sound plausible to you?

Tosafot in Sukkah brings two explanations from the midrash:
1. Grasp something that has a fixed limit, and not something that has no fixed limit.
That explanation is valid only for cases where the larger measure is unlimited, as in the rule “the plural of a minority is two” — the smaller measure is known, while the larger measure has no limit.

The smaller measure is certainly correct (because it is included within the larger measure), while the larger measure is doubtful, and therefore the smaller measure is certain.

In both explanations there is no doubt regarding the larger measure; rather, since the Torah spoke without specification, surely it meant the larger measure.

In the case of “and perhaps say it is the egg of the bar yokhani,” the first explanation fits: if the smaller measure were not fixed — a chicken egg — there would be no egg we could determine as the measure.
The statement “and perhaps say it is the egg of the bar yokhani” is a question — it cannot be that liability would apply only upon eating the egg of the bar yokhani (whose egg destroyed 60 cities — without getting into the meaning of the exposition), and it is therefore necessary that the measure be smaller, and since “it has no fixed limit,” the smaller measure is established.

Ezra, in the case of food impurity (where only the first explanation fits), are you saying that if the largest egg we had ever seen were only twice the size of a chicken egg, then they really would have gone by the larger egg? If so, today, when they estimate that they know all the egg sizes that exist and that existed then, they should go by the largest one.

It has nothing whatsoever to do with information about the largest egg, and if the sages didn’t have that information, they wouldn’t have made a mistaken decision when they knew they lacked the real information.
It makes no sense for an eating measure to be 20 times an egg (the weight of an ostrich egg)… and therefore there is no measure that can be established other than the small one. That too is what the Talmud meant by “and perhaps say it is the bar yokhani” — would the measure be something that a person cannot eat?
Your question, as if this has practical ramifications, is not relevant, because as far as I recall this is the initial assumption.

What’s illogical about an eating measure for some matter being 20 times an egg? And in food impurity the discussion is not about eating at all, but about the food that will impart impurity (or become impure), so what is illogical about a measure that a person cannot eat?
In any case, what is wrong with Rabbi Michael Abraham’s explanation above that we need to start thinking about what is logical and what isn’t? Everywhere the question is: what would we do without the law of the measure? And the answer is that we would do it with any amount whatsoever, and the measure comes to cancel the rule of any amount and set it at a defined quantity, so we move away as little as possible and minimize the novelty. With first shearing, we move away from any amount toward a sash. With food impurity, we move away from any amount toward a chicken egg, not a bar yokhani or an ostrich. That is similar to the second explanation you brought, that the smaller measure is certain, but in a more precise way that also includes food impurity (where there, on the contrary, only the larger measure is certainly impure / impurity-imparting, since it includes the smaller measure, and not vice versa). And likewise it makes sense regarding the make-up offering of the Festival of Weeks: without an additional verse there would be no make-up offering at all, so we add as little make-up as possible.
Indeed, I was mistaken, and my question as if this had practical implications is irrelevant, because it seems that Rabbi Elazar’s statement there was rejected anyway because of tiny bird eggs.

You’re right. I was mistaken regarding the context in which the egg-bulk measure was stated.
I still think the reason that only an egg-bulk imparts impurity is because of significance — the significance is of an important eating measure, not of a quantity of a kilo and a half.

Rabbi Michi’s answer makes sense. I think the law and the measure were stated together, and one has to minimize the law as much as possible. Regardless of whether it comes out stringent or lenient.

But to minimize the law of food impurity would mean requiring the larger measure (so that only in that case would the law of food impurity apply), not the smaller measure. That’s the whole point.

Exactly.
That’s why I tried answering in a different way.

Ah, okay.

It’s not clear to me how you interpret the phrase “if you grasp too much” in terms of significance. And why significance also doesn’t answer the Talmud’s next question about tiny bird eggs.
By the way, according to your approach, when there is doubt what the measure of “flock” is — 2 or 5 — would there also have been room to say “if you grasp the lesser”?

Tirgitz, regarding the flock — sounds plausible to me.

Tirgitz, the Talmud’s question can be interpreted this way: after all, there are larger eggs, like that of the bar yokhani, and if so the measure should be larger. The answer is that although there are larger eggs, the measure is not the bar yokhani (the largest egg), and therefore the smaller measure is the correct one.
I’m aware of the difficulty, and it seems Rabbi Michi’s explanation is better.
It may be that “if you grasp too much” is a rule that always determines in the stringent direction (as Tosafot explained in Yoma 82b).

Ezra, yes indeed. A search shows that there are very few appearances of this rule in the Talmud, so it’s fairly easy to check each proposal. The harder part, and to my taste also the more interesting one, is to check the positive predictive power of the theory — meaning, given such a rule, to go and check all the places where the Talmud did not use “if you grasp too much,” and see whether the theory really does not incorrectly predict that they should have used it there. Then one also has to examine its relation to other rules like “it is enough for the derivation from an inference to be like the source law,” or “we compare toward stringency,” or “Scripture did not come to speak obscurely,” and why it is not used in the laws of doubt. At some point I’ll look in Otzar HaHokhmah; presumably this has already been treated from every angle.