- עילאה גבר או תתאה גבר
It was stated, חם לתוך חם דברי הכל אסור – If a hot food fell into a hot beverage or vice versa, and it is a case, as Rashi explains, where the absorption would make it forbidden, such as meat with milk or issur with heter, everybody agrees that that it is assur. צונן לתוך צונן דברי הכל מותר – If something cold fell into something cold, all agree that it is mutar. חם לתוך צונן וצונן לתוך חם – If something hot fell into something cold or something cold fell into something hot, it is a machlokes. Rav says, עילאה גבר – the upper one dominates, which Rashi explains means that if something hot falls into something cold, the "upper" one heats up the "lower" one, before the "lowe"r one can cool it. Since they are then both heated, they absorb from each other. On the other hand, if something cold fell into something hot, the falling one cools off the "lower" one, before the "lower" one can heat the falling one. Shmuel says, תתאה גבר – the lower one dominates. Rashi comments that although the halachah generally follows Rav over Shmuel in matters of איסורים, in this case the halachah follows Shmuel because he is supported by two Baraisos brought in the Gemara.
- מליח הרי הוא כרותח כבוש הרי הוא כמבושל
It was taught in a Baraisa, צונן לתוך צונן מדיח – If something cold was placed into something cold, one merely rinses it. Rav Huna said, לא שנו אלא שלא מלחו – They taught this only concerning a case where one had not salted the forbidden item, but if one had salted it, the other one is forbidden, for Shmuel said, מליח הרי הוא כרותח – That which is salted is like that which is hot, which means that salted food has the same capacity as hot food to transfer its juices. However, it does not absorb juices like a hot food. Therefore, if the permitted component was salted it would not absorb the prohibited juices . Shmuel also states, כבוש הרי הוא כמבושל – that which was marinated is like that which is cooked. Rashi explains that if a permitted food was marinated in vinegar together with a forbidden food, it is considered as though they have been cooked together, and the forbidden food is presumed to have spread throughout the entire permitted food.
Rava said that Shmuel’s statement that that which is salted is like that which is hot, was said only, שלא נאכל מחמת מלחו – where the salted food is unfit to be eaten on account of its saltiness. Rashi explains that the food is unpleasant to eat unless it is rinsed.
- Does ריח transfer?
Rav said, בשר שחוטה שמן שצלאו עם בשר נבילה כחוש אסור – If fatty meat of a shechted animal was roasted in an oven, together with lean meat of a neveilah, it is forbidden. מפטמי מהדדי – They are fattened by each other. Rashi explains that the two meats do not touch, yet the kosher meat absorbs the aroma of the neveilah. Even though the lean neveilah does not give off a strong aroma, it absorbs the aroma of the fatty kosher meat, is subsequently "fattened," and then emits aroma which is absorbed by the kosher meat. Levi said that even if lean meat of a shechted animal was roasted together with the fatty meat of a neveilah, it is permitted because, ריחא בעלמא הוא וריח לאו מילתא – This is a case involving the transfer of aroma, and aroma is not a factor. Levi ruled in an actual case in the house of the Reish Galusa, involving a goat that was roasted near a pig, that the goat was permitted.