Our Gemora states that ma’aser sheini produce is regarded as something that will otherwise become permitted (since it may be eaten in Yerushalayim, or it can be redeemed), and there is a principle that any item that will eventually become permitted is not nullified even when intermingled with a thousand items of its like.
The Rishonim disagree regarding a food item that the Gemora is uncertain if it is forbidden or not and it remains unresolved. The inquiry will remain in that state until Eliyahu Hanavi clarifies it for us. The Ohr Zarua maintains that this is regarded as “something which can become permitted,” since there is a possibility that Eliyahu will say that it is permitted. The Rashba disagrees and he explains: If Eliyahu will decide that the food is forbidden, it will emerge that this item will never be permitted. If he will rule that it is permitted, it actually was never forbidden. Either way, he argues, it cannot be labeled as “something which can become permitted.” The Bach cites a Mordechai that it is not considered “something which can become permitted,” for by the time Eliyahu will permit it, the food will be already ruined.
The Chasam Sofer cites the following question from the Rav in Frankfurt: Chazal write that a pig is called a “chazir,” for in the future, Hashem will reverse the prohibition of the pig and it will be permitted. If so, according to those Rishonim, pig should be regarded as “something which can become permitted”?
The Chasam Sofer answers based upon that which was written in the Toldos Yitzchak: The Torah forbids animals that do not have split hooves, or those that do not chew their cud because those animals are naturally conceited; they trample with their feet and they have a poison inside of them, which is extremely dangerous for a Jew to eat. The animals that do not digest their food easily and they are compelled to chew their cud; those animals are permitted to eat.
If so, explains the Chasam Sofer, there will be no change in halacha regarding the pig. It was forbidden and will remain forbidden. Rather, Hashem will change the nature of the pig and it will begin to chew its cud. That is why it will be permitted then. Accordingly, the only pigs that will be permitted then, are those that will be born after this change occurs; however, the pigs that were in existence prior to that will remain forbidden. This is why a pig is not classified as “something which can become permitted.”
Something that can become Permitted
(Davar she’yeish lo Matirin)
The Mishna states: If one makes a neder prohibiting himself from wine, he is permitted in cooked food which has in it the taste of wine. However, if he said, “Konam this wine that I will not taste,” and it fell into a cooked dish, if it contains enough to impart flavor to the entire mixture, it is forbidden.
This would imply that if there is not enough to give flavor, it would be permitted. The Ra”n quotes his teachers who ask the following: Something which is forbidden on account of a neder is “something that can become permitted” (davar she’yeish lo matirin), and we have established that anything that can become permitted is not nullified even in a thousand!?
They answer that when we say that it is not nullified even in a thousand, that refers to something that has been mixed with its own kind. But here, when it says, “and it became mixed,” it is referring to something else that is not the same kind, like the case of eggs that were cooked with it. Anything that is mixed with something else that is not its kind is permitted, provided that it does not give flavor, even if it is “something that can become permitted.” The Ra”n cites proof to this from a Mishna in Chalah and a Yerushalmi.
They, therefore, objected to the statement of the Ri”f in Meseches Chulin concerning bread that was baked in an oven with roasted meat. The Gemora states that it is forbidden to eat it with a dairy sauce even though it has been established that we are not halachically concerned with vapors. The reason it is forbidden is because the bread is “something that can be permitted,” since one may eat it together with meat. For that reason, it is not nullified, even in a thousand. It is evident from the Ri”f that he maintains that “something that can be permitted” is not nullified even in something that is not its kind.
The Ra”n, however, agrees to the Ri”f. When the Mishna here says that “something can become permitted” becomes nullified in something that is not its own kind, that is referring to something that is forbidden now, but will become permitted in the future, like nedarim. For the Ra”n has the following question: Since according to the Chachamim, all forbidden things become nullified in their own kind just as in a different kind, why did the Chachamim make a distinction in the case of “something that can become permitted,” between its own kind and a different kind? The reason is as follows: The Chachamim and Rabbi Yehudah disagree whether or not something can be nullified in its own kind. Rabbi Yehudah maintains that a forbidden item is not nullified in its own kind, because anything that is similar to another thing does not weaken and nullify it; rather, it preserves it and strengthens it.
The Chachamim disagree and hold that a forbidden item and something which is permitted are not similar to each other, even if they are the same kind. This is because one is forbidden and one is permitted. For it is not fitting to follow the similarity of their substance, but rather the difference in their being forbidden and permitted. It is for this reason that the Chachamim learned concerning “something that can be permitted” for the sake of being strict towards the opinion of Rabbi Yehudah. For since the forbidden item is not completely different from the permitted one, because the forbidden one will eventually become permitted, we say that it is not nullified in its own kind. It will only become nullified when mixed with a different kind, for the difference that exists between one kind and another will make up for the equality that is added here because it is “something that can be permitted.” It is the difference between kinds that is the cause of nullification, and equality interferes with nullification.