Zevachim 78b

אֶלָּא מִין בְּשֶׁאֵינוֹ מִינוֹ – בְּטַעְמָא, מִין בְּמִינוֹ – בְּרוּבָּא.

Rather, one must say that according to Reish Lakish, in a case of a type of food mixed with food not of its own type, such as wheat flour and rice flour, whose tastes are different, the status is determined by the flavor. Therefore, if the dough tastes like wheat, it has the halakha of a dough made from wheat. But if it is a type of food mixed with food of its own type, e.g., a mixture of piggul and notar meat, which is the case addressed by Reish Lakish, the status of the mixture is determined by the majority.

וּנְשַׁעֵר מִין בְּמִינוֹ כְּמִין בְּשֶׁאֵינוֹ מִינוֹ! דִּתְנַן: נִתְעָרֵב בְּיַיִן – רוֹאִין אוֹתוֹ כְּאִילּוּ הוּא מַיִם. מַאי, לָאו רוֹאִין אוֹתוֹ לַיַּיִן כְּאִילּוּ הוּא מַיִם?

The Gemara suggests: But let us estimate in a case of a type of food mixed with food of its own type as though it were a mixture of a type of food mixed with food not of its own type, and if so, the minority is not nullified if it is substantial enough to impart flavor to the majority. As we learned in the mishna: If the blood of an offering was mixed with wine, one considers it as though it is water. Although blood and wine certainly have different flavors, in the case of the mishna the determinative factor is not the taste of the mixture, but the appearance. Since they share the same appearance, they are considered a case of a substance in contact with the same type of substance. What, is it not correct to explain the mishna as stating that one views the wine as though it is water, i.e., a substance of a different type, and if the mixture would have the appearance of blood if the wine were water it is fit for presentation, despite the fact that the blood is not the majority?

לֹא; רוֹאִין אוֹתוֹ לַדָּם כְּאִילּוּ הוּא מַיִם. אִי הָכִי, ״בָּטֵל״ מִיבְּעֵי לֵיהּ!

The Gemara answers: No, this is not the explanation of the mishna. Rather, it means that one views the blood as though it is water, i.e., it is unfit for presentation, since it is as though one presented water on the altar. The Gemara questions this explanation: If so, the tanna of the mishna should have said: The blood is nullified.

וְעוֹד, תַּנְיָא רַבִּי יְהוּדָה אוֹמֵר: רוֹאִין אוֹתוֹ כְּאִילּוּ הוּא יַיִן אָדוֹם; אִם דֵּיהָה מַרְאֵהוּ – כָּשֵׁר,

And furthermore, it is taught in a baraita ( Tosefta , Mikvaot 7:4): With regard to a ritually impure bucket containing a certain amount of white wine or milk that one immersed in a ritual bath, Rabbi Yehuda says: Although the appearance of the white wine or milk is not discernible in the water of the ritual bath that enters the bucket, one views the white wine or milk as though it is red wine, and makes the following determination: If its conjectured red appearance would pale due to the water that enters the bucket, the wine or milk is nullified by the water. Therefore, the act of purification is fit, and the bucket is ritually pure.

וְאִם לָאו – פָּסוּל!

Rabbi Yehuda continues: But if its conjectured red appearance would not pale, the act of purification is unfit, and the bucket remains ritually impure. This is a case in which a substance was mixed with another substance of similar appearance, as white wine and milk have a similar appearance to the water, and yet it is treated as a mixture of a substance with a different type of substance, and it is not nullified in a majority.

תַּנָּאֵי הִיא; דְּתַנְיָא: דְּלִי שֶׁיֵּשׁ בּוֹ יַיִן לָבָן אוֹ חָלָב וְהִטְבִּילוֹ – הוֹלְכִין אַחַר הָרוֹב. רַבִּי יְהוּדָה אוֹמֵר: רוֹאִין אוֹתוֹ כְּאִילּוּ הוּא יַיִן אָדוֹם; אִם דֵּיהָה מַרְאֵהוּ – כָּשֵׁר, וְאִם לָאו – פָּסוּל.

The Gemara explains: One cannot cite a proof from the opinion of Rabbi Yehuda, as this is a dispute between tanna’im , and the ruling follows the opinion of the Rabbis, who disagree with the opinion of Rabbi Yehuda. As it is taught in that baraita : With regard to a ritually impure bucket in which there is white wine or milk, and one immersed it in a ritual bath, one follows the majority, i.e., if the majority of the contents of the bucket is now water from the ritual bath, it is pure. Rabbi Yehuda says: One views the white wine or milk as though it is red wine and makes the following determination: If its conjectured red appearance would pale due to the water that enters the bucket, the act of purification is fit, and the bucket is ritually pure. But if its conjectured red appearance would not pale, the act of purification is unfit, and the bucket remains ritually impure.

וּרְמִינְהִי: דְּלִי שֶׁהוּא מָלֵא רוּקִּין, וְהִטְבִּילוֹ – כְּאִילּוּ לֹא טָבַל.

And the Gemara raises a contradiction to the opinion of Rabbi Yehuda from a mishna (see Mikvaot 10:6): If one had an impure bucket that is filled with spittle and one immersed it in a ritual bath, the spittle is considered an interposition between the water of the ritual bath and that of the bucket, and therefore it is as though he did not immerse it.

מֵי רַגְלַיִם, רוֹאִין אוֹתוֹ כְּאִילּוּ הֵן מַיִם.

If the impure bucket was full of urine and he immersed it, although urine is slightly different in appearance than water, one views the urine as though it is water, and therefore once the urine is in contact with the ritual bath it is considered connected to the water, and it is not an interposition preventing the bucket from becoming ritually pure.

מָלֵא מֵי חַטָּאת – עַד שֶׁיִּרְבּוּ הַמַּיִם עַל מֵי חַטָּאת.

The mishna continues: If the impure bucket was filled with water of purification, the bucket is not purified until the water of the ritual bath that enters the bucket becomes greater in quantity than the water of purification it contains, thereby nullifying it in a majority.

מַאן שָׁמְעַתְּ לֵיהּ דְּאִית לֵיהּ ״רוֹאִין״ – רַבִּי יְהוּדָה; וְקָתָנֵי דְּסַגִּי לֵיהּ בְּרוּבָּא!

The Gemara explains the contradiction: Whom have you heard who accepts this reasoning of: One views, which appears in this mishna with regard to urine? It is Rabbi Yehuda, as stated in the baraita cited above. And yet the mishna teaches that a majority suffices to nullify the water of purification that became mixed with water, and it is not considered as though it is red wine. This conflicts with the ruling of Rabbi Yehuda with regard to white wine and milk.

אָמַר אַבָּיֵי: לָא קַשְׁיָא;

Abaye says: This is not difficult;