Ḥizkiyya says: If the volume of the water and the wine was increased by the forbidden wine, i.e., the forbidden wine fell in last, the mixture is forbidden, because the forbidden wine renders the permitted wine forbidden by the principle of a substance in contact with the same type of substance, and the water does not nullify the forbidden wine. But if the volume of the water and the forbidden wine was increased by the permitted wine, i.e., there was a mixture of wine used for a libation and water, and the wine used for a libation was nullified by the water and then permitted wine fell into the mixture, in such a case the permitted wine is not rendered forbidden by the forbidden wine that had already been nullified, and so the entire mixture is permitted.

And Rabbi Yoḥanan says: Even if the volume of the permitted wine and the water was increased by the forbidden wine, the mixture is permitted.

Rabbi Yirmeya said to Rabbi Zeira: Shall we say that Ḥizkiyya and Rabbi Yoḥanan disagree with regard to the issue that is the subject of the dispute between Rabbi Eliezer and the Rabbis?

As we learned in a mishna (Orla 2:11): In the case of non-sacred leaven and teruma leaven that fell into a non-sacred batch of dough, and neither is this one alone potent enough to cause the dough to become leavened, nor is that one alone potent enough to cause the dough to become leavened, and they combined and caused the dough to become leavened, there is a dispute as to whether this dough has the status of teruma, and is therefore forbidden to non-priests, or non-sacred bread.

Rabbi Eliezer says: I follow the final element that fell into the dough. If the teruma fell in last, the dough is forbidden to non-priests. And the Rabbis say: Whether the forbidden item, i.e., the teruma, fell in first or whether it fell in last, the dough is not forbidden unless there is enough of the forbidden leaven alone to cause the dough to become leavened. Apparently, Ḥizkiyya holds in accordance with the opinion of Rabbi Eliezer that if the forbidden substance is mixed in last, the mixture is rendered forbidden, and Rabbi Yoḥanan holds in accordance with the opinion of the Rabbis that if the amount of the forbidden substance is not sufficient in and of itself to render the mixture forbidden, the mixture is permitted.

The Gemara responds: And how can you understand that this is the same dispute? But doesn’t Abaye say: Rabbi Eliezer taught that the mixture is permitted when the permitted leaven fell in last only in a case when one first removed the forbidden leaven before the permitted leaven fell into the dough and made it rise. But if one did not first remove the forbidden leaven, the dough is forbidden even if the permitted leaven fell in last. According to Abaye’s interpretation, in accordance with whose opinion does Ḥizkiyya state his ruling with regard to a mixture of forbidden wine, permitted wine, and permitted water, that if the forbidden wine was mixed in last the mixture is forbidden? According to the Rabbis the mixture should be permitted in any event, as there is not enough forbidden wine to render the mixture forbidden, and according to Rabbi Eliezer, even if the permitted wine was mixed in last the mixture should be forbidden, as the forbidden wine was not removed.

Rather, here Ḥizkiyya and Rabbi Yoḥanan disagree concerning the principle that with regard to a mixture of a forbidden substance and a permitted substance of the same type, and a permitted substance of a different type, one considers the permitted substance of the same type as though it were nonexistent so that the substance of the other type can nullify the forbidden substance. Ḥizkiyya is not of the opinion that one considers it as though it were nonexistent, whereas Rabbi Yoḥanan is of the opinion that one considers it as though it were nonexistent, and so he maintains that in any event the water nullifies the forbidden wine, and the permitted wine in the mixture is disregarded.

The Gemara asks: And is Rabbi Yoḥanan of the opinion that one considers the permitted substance of the same type as though it were nonexistent? But didn’t Rabbi Asi ask Rabbi Yoḥanan the following question: If one had two cups of wine, one non-sacred and one of teruma, and he diluted them with water and mixed them together, and there is sufficient water in each of the cups to nullify the teruma wine, what is the halakha? Is the non-sacred wine, which is the same type of substance as the teruma wine, considered to be nonexistent, and the water in the mixture nullifies the teruma wine, or does the teruma wine render the non-sacred wine forbidden, and the water in both cups is insufficient to nullify the combined wine? And Rabbi Yoḥanan did not resolve the dilemma for him, indicating that he did not have a set opinion on the matter.

The Gemara answers: Initially he did not resolve the dilemma for him, but ultimately he resolved for him that the permitted substance of the same type is considered as though it were nonexistent. It was also stated that this was Rabbi Yoḥanan’s ultimate opinion, as Rabbi Ami says that Rabbi Yoḥanan says, and some say that it is Rabbi Asi who says that Rabbi Yoḥanan says: If one had two cups of wine, one non-sacred and one of teruma, and he diluted them with water and mixed them together, and there is sufficient water in each of the cups to nullify the teruma wine, one considers the permitted wine as though it were nonexistent, and as for the rest, the teruma wine, the volume of the water is greater than the volume of the wine and nullifies it.

§ The mishna states that this is the principle: A substance in contact with the same type of substance renders the mixture forbidden with any amount of the forbidden substance, but a substance in contact with a different type of substance renders the mixture forbidden only in a case where it imparts flavor to it.

The Gemara presents an amoraic dispute with regard to this principle: Rav and Shmuel both say: With regard to any food forbidden by the Torah that becomes mixed with permitted food, if the permitted food is of its own type, then even any amount of the forbidden substance renders the entire mixture forbidden. If the forbidden food is mixed with another type of substance, then the mixture becomes forbidden only in a case where there is enough of the forbidden food to impart flavor to the mixture.

According to Rav and Shmuel, what is added by the statement in the mishna: This is the principle, etc.? This is stated to include any food forbidden by the Torah, and not only wine used for a libation.

Rabbi Yoḥanan and Reish Lakish both say: With regard to any food forbidden by the Torah that falls into a mixture, whether of its own type of food or another type of food, the mixture is forbidden in a case where there is enough of the forbidden item to impart flavor to the mixture. This is the halakha except for the cases of untithed produce and wine used for a libation, which render a mixture with their own type of food forbidden in a case where any amount of the forbidden food was mixed with the permitted food; but if they are mixed with another type of substance, the mixture is forbidden only in a case where it imparts flavor to it. And according to this opinion, the statement in the mishna: This is the principle, etc., is stated to include the case of untithed produce, which is not mentioned in the mishna explicitly.

It is taught in a baraita in accordance with the opinion of Rav and Shmuel, and it is taught in another baraita in accordance with the opinion of Rabbi Yoḥanan and Reish Lakish.

The Gemara elaborates: It is taught in a baraita in accordance with the opinion of Rav and Shmuel: With regard to any food forbidden by the Torah that becomes mixed with a permitted food, in a case where the permitted food is of its own type, then even any amount of the forbidden substance renders the entire mixture forbidden. But in a case where the forbidden food was mixed with another type of substance, then the mixture becomes forbidden only in a case where there is enough of the forbidden item to impart flavor to the mixture.

It is taught in another baraita in accordance with the opinion of Rabbi Yoḥanan and Reish Lakish: With regard to any food forbidden by the Torah that falls into a mixture, whether of its own type of food or another type of food, the mixture is forbidden in a case where there is enough of the forbidden food to impart flavor to the mixture. This is the halakha except for the cases of untithed produce and wine used for a libation, which render a mixture with their own type of food forbidden in a case where any amount of the forbidden food was mixed with the permitted food; but if they are mixed with another type of substance, the mixture is forbidden only in a case where they impart flavor to it.

The Gemara asks: According to the opinion of Rabbi Yoḥanan and Reish Lakish, why are untithed produce and wine used for a libation treated more stringently than other forbidden foods? Granted, wine used for a libation is treated stringently due to the severity of idol worship, but with regard to untithed produce, what is the reason that any amount of it that is mixed with permitted food of its own type renders the mixture forbidden?

The Gemara answers: Just as it assumes its permitted status, so it assumes its forbidden status, as Shmuel says: Even one grain of wheat given as teruma exempts the entire heap of grain from the obligation of teruma. Since any amount of teruma given renders the entire heap of produce permitted, any amount of untithed produce also renders the entire mixture forbidden. And this is also taught in a baraita: With regard to what situation did the Sages say that any amount of untithed produce renders a mixture forbidden? It is with regard to untithed produce that becomes mixed with its own type, but with regard to untithed produce that becomes mixed with another type, the mixture is forbidden only in a case where the untithed produce imparts flavor to it.