Pesachim 41A

אחרוסת קאמר מר, או אחרדל קאמר מר? אמר ליה: למאי נפקא מינה?

Did the Master say this statement with regard to ḥaroset, or did the Master say it with regard to mustard? He said to him: What is the practical difference whether he was referring to ḥaroset or mustard? Both of these are mentioned together, and the same halakha applies to both.

לדרב כהנא. דאמר רב כהנא: מחלוקת לתוך החרדל, אבל לתוך החרוסת ⁠— דברי הכל ישרף מיד.

He said to him: There is a difference with regard to that which was stated by Rav Kahana, as Rav Kahana said: The dispute between R' Meir and the Rabbis concerns a case in which flour was added to mustard. However, if flour was added to ḥaroset, everyone agrees that it must be burned immediately. Rav Naḥman bar Yitzḥak was asking Rav Huna, son of Rav Yehuda, whether he disagrees with Rav Kahana and maintains that the Rabbis dispute the halakha in the case of ḥaroset as well.

אמר ליה: לא שמיע לי, כלומר לא סבירא לי.

He said to him: I did not hear about this statement; that is to say, I do not hold in accordance with it. I do not distinguish between these two cases, as in my opinion the Rabbis permit one to eat even this ḥaroset.

אמר רב אשי: כוותיה דרב כהנא מסתברא, מדאמר שמואל: אין הלכה כרבי יוסי. מאי לאו? צמותי הוא דלא צמית, הא חמועי מחמעא.

Rav Ashi said: It is reasonable to rule in accordance with the opinion of Rav Kahana, from the fact that Shmuel said that the halakha is not in accordance with the opinion of R' Yosei, who maintains that vinegar will prevent grain from becoming leavened. What, isn’t it correct to infer from here that vinegar added to flour does not shrink the grain and will even leaven it? According to this explanation, food that contains vinegar, e.g., ḥaroset, is likely to be leavened immediately, as claimed by Rav Kahana.