Gemara

(Abaye): A Yisrael may not smell a Nochri's wine through Bas Tiha. a hole in the cork, or a straw partially inserted in a barrel).

(Rava): He may smell it.

Abaye holds Re'ach Milsa Hi (smell is important). Rava disagrees.

Support (Rava, for himself - Mishnah #1): If bread was baked in an oven heated with cumin of Terumah, Yisraelim may eat the bread, because it does not absorb the taste, only the smell.

Rejection (Abaye): There, the Isur (the Terumah) is burned.

(Rav Mari): Tana'im argue as Abaye and Rava do.

(Mishnah #2 - R. Meir): If one removed hot bread from an oven, and put it on a barrel of Terumah wine, the bread is forbidden to a Zar;

R. Yehudah permits it;

R. Yosi permits wheat bread, but forbids barley bread, for barley absorbs.

Suggestion: R. Meir says that Re'ach Milsa Hi, and R. Yehudah says that it is not.

Rejection: Indeed, Rava cannot hold like R. Meir, but even R. Yehudah could hold like Abaye!

(Reish Lakish): All forbid warm bread that was put on top of an open barrel. All permit cold bread on top of a closed barrel. They argue about warm bread on a closed barrel and cold bread on an open barrel.

Bas Tiha is like warm bread on an open barrel!

Pesachim 76b (Rav): If fat Shechutah (slaughtered meat) was roasted with lean Neveilah meat, it is forbidden.

The Neveilah absorbs fat, and then it gives off a smell.

(Levi): We permit even lean Shechutah roasted with fat Neveilah.

This is because it absorbs a mere smell. Smell is insignificant.

A case occurred, and Levi permitted a kid was roasted with a pig.

Question (Beraisa): We may not roast two Pesachim together due to mixing. (The tastes mix, and one tastes another's Pesach.)

Answer: No, it is forbidden lest the two animals get mixed up.

Support (Seifa): We forbid even a goat and a lamb.

If the concern is transfer of taste, this is like two goats!

(R. Yirmeyah): Rav explains that we permit when it is as if they were cooked in two pots. (A mound separates the two spits.) The Beraisa forbids due to mixing of tastes. Even if it is as if they are in two pots (and the tastes will not mix), it is forbidden lest they get mixed up, even a goat and a lamb.

(Rav Mari): R. Meir and R. Yehudah (Mishnah #2) argue about this:

Rejection: Indeed, Levi must say that Tana'im argue about this, but Rav can say that all agree that Re'ach Lav Milsa Hi, like Reish Lakish taught. Meats roasted together are like warm bread on an open barrel!

(Rav Kahana brei d'Rav Chinena - Beraisa): If bread was baked in an oven with Tzeli (roasting meat), it may not be eaten with Kutach (a dairy dip).

A case occurred in which fish was roasted with meat. Rava of Parzakiya forbade eating it with Kutach. Mar bar Rav Ashi forbade eating it even with salt (i.e. alone), for a mixture of fish and meat can cause odor and Tzara'as.

Rishonim

Rif (Chulin 32a): Rabanan rule like Levi. They support this from Avodah Zarah, in which Rava and Abaye argue about whether Re'ach Milsa Hi. We rule like Rava against Abaye with only six exceptions, and this is not one of them. Some rule like Rav, for his reasoning is better. The Beraisos about bread put on top of a barrel and bread baked with meat support him. A case occurred, and Rava of Parzakiya forbade eating fish (roasted with meat) with Kutach, like Rav. I hold like the first opinion. The Beraisa about bread on a barrel was difficult only due to Reish Lakish's Perush. Levi was Reish Lakish's Rebbi, and Rava is Basra (chronologically later). They argue with Reish Lakish. The Halachah follows Basra. Rav holds like R. Meir, and Levi holds like R. Yehudah, whom we follow against R. Meir. R. Yosi agrees with R. Yehudah. He forbids barley bread because it absorbs actual wine, not just the smell.

Ran (DH Abaye): Abaye and Rava do not argue about whether one may benefit from smell of Isur, for the Gemara says that they argue like the Tana'im about bread on top of Terumah wine. One may benefit from smelling Terumah! Also, we hold like R. Shimon, who permits Davar she'Eino Miskaven (something that one does not intend for, and it is not sure that it will occur). Surely here we do not discuss a Rasha who wants to benefit from Yayin Nesech! Even if it is a Pesik Reishei (an inevitable consequence), we do not forbid a Pesik Reishei regarding Hana'ah. This is why vendors of Shatnez may wear it in the sun or rain, as long as they do not intend for benefit (Pesachim 26a). Rather, Abaye and Rava argue about whether smelling is like drinking. Abaye holds that it is, therefore, it is forbidden even without intent. Mis'asek (one who was engaged in something, and did something without intent) is liable for forbidden foods, for he benefited (Sanhedrin 62b).

Rambam (Hilchos Ma'achalos Asuros 9:23): If bread was baked with Tzeli, or fish was roasted in one oven with meat, one may not eat it with milk.

Rosh (Avodah Zarah 5:8): The Rashbam says in the name of Rashi that the Halachah follows Levi, for he holds like Rava. Bahag agrees. R. Tam rules like Rav, for Rav Kahana's Beraisa supports him. They ruled like Rav in an actual case, and Mar bar Rav Ashi holds like Rav. The Halachah follows Mar bar Rav Ashi everywhere, except for reversing an oath. Here Rava holds that the smell of a fatty Neveilah is significant. There are different levels of smell. All forbid hot bread on an open barrel, like Reish Lakish. Rav and Levi argue about the smell of a fatty Neveilah. Bas Tiha is less than this. All permit cold bread on a corked barrel. The Gemara did not bring the case of cooking with cumin, for it is unlike fatty meat. This refers to their small ovens, in which they covered the openings, so the smell of one (food) entered the other. There is no concern in our ovens, in which the opening is open. The Halachah follows Rava in all of these.

Hagahos Ashri: We hold that Re'ach Milsa Hi l'Chatchilah. Therefore, if bread was baked with Tzeli, one may not eat it with Kutach. Since one can eat it without Kutach, this is l'Chatchilah. B'Di'eved it is permitted, even though Re'ach Milsa Hi. L'Chatchilah one may bake Pashtida (meat pie), which is covered above, in an oven with bread, for our ovens are big. However, if the lard drips outside the Pashtida and is absorbed in the oven, even if the bread is far away, one may not eat it even with salt. Therefore, it is good to be careful not to bake any covered meat with bread, lest the lard drip and he will be unaware. Rather, he bakes the Pashtida, and ignites the oven and bakes the bread.

Poskim

Shulchan Aruch (YD 97:3): If bread was baked with meat, or fish was roasted in one oven with meat, one may not eat it with milk. This refers to a small oven. If the oven was big and holds 12 Esronim, and the opening is open, one may roast them together, as long as they do not touch. If the Tzeli was covered, or if the hole in a meat pie was covered, it is permitted even in a small oven.

Beis Yosef (DH u'Mah): Rashi and the Tur rule that Re'ach Lav Milsa Hi. R. Tam rules that Re'ach Milsa Hi. Tosfos (Pesachim 76b DH Asrah) says about R. Tam's opinion that in our big ovens, one may bake bread with Pashtida, for it is covered well. It is like two pots. It seems that we permit even (if it was baked with) a cheese pastry, for there is much air in the oven and the heat spreads. Semag, Semak, the Mordechai and Hagahos Maimoniyos (Ma'achalos Asuros 9:90/100) say that R. Tam is stringent only in small ovens in the days of Chachamim (of the Gemara), in which there is much taste of the fat. In our big ovens, one may bake bread with Tzeli. Semak says that an oven that holds 12 Esronim is called big.

Beis Yosef (ibid.): Some editions of Hagahos Maimoniyos (15:33) say that even the opinion that Re'ach Lav Milsa Hi says so only for their ovens, in which the opening is at the top. In our ovens, the opening is at the side. It holds in the taste and fattens whatever is next to it. This is why all forbid l'Chatchilah, unlike I explained above (9:90/100). I do not know who wrote this Hagahah. It is unlike all Rabanan, who are more lenient about our ovens! The Ba'al ha'Ma'or (Pesachim 19a, DH Od) says that some permit if the oven is wide, for there is not so much (smell in the) air. It seems that he holds that it suffices to be a little wide. It need not hold 12 Esronim.

Shach (3): Here we discuss only Isur. The danger of fish with meat is discussed in Rema (106:2).

Shach (4): Even though we permit (108:1) meat cooked with Neveilah in one oven, even if it is small, here one can eat it without milk, so this is l'Chatchilah.

Shach (5): An Isaron is the Shi'ur of dough from which one must separate Chalah, i.e. the volume of 43 and a fifth eggs.