ZEH V'ZEH GOREM [Zeh v'Zeh Gorem]
48b (Mishnah): One may plant vegetables under an Asherah in winter (when its shade is bad for them), but not in summer. One may not plant lettuce under it in summer or winter (shade is always good for lettuce).
R. Yosi forbids even vegetables in winter, for the leaves fall and fertilize them.
Question: Here, R. Yosi forbids Zeh v'Zeh Gorem and Chachamim permit. Elsewhere, each holds just the opposite!
(Mishnah - R. Yosi): One grinds up (idolatry) and throws the dust to the wind, or casts it to the sea.
Chachamim: No. This would fertilize the ground (that it is deposited on). We may not get any benefit from idolatry - "Lo Yidbak b'Yadcha Me'umah Min ha'Cherem."
Answers: The opinions must be switched. Alternatively, R. Yosi permits throwing dust of idolatry to the wind, for it will be scattered and not fertilize anything. Chachamim permit like Rav Mari taught, because the gain due to the leaves (fertilizer) is offset by the loss due to the shade.
49a (Mishnah - R. Eliezer): If Se'or (a fermenting agent) of Chulin and of Terumah fell into a dough, and there was not enough of either one to ferment the dough, and together they fermented it, the dough is like the last one that fell in (if Terumah fell in last, it is like Terumah);
Chachamim say, no matter which fell in last, it is like Chulin unless there was enough (Se'or of) Terumah to ferment it without the Chulin.
(Abaye): R. Eliezer permits (when the Chulin fell in last) only if the Terumah was removed before the Chulin fell in. If not, it is forbidden. (He forbids Zeh v'Zeh Gorem, and Chachamim permit.)
Rejection: Perhaps also R. Eliezer permits Zeh v'Zeh Gorem (e.g. if they fell in at the same time). He forbids here only because we attribute the entire action to the final cause, whether or not the first cause was removed.
(Mishnah): If wood from an Asherah was used to bake bread, it is forbidden. If it became mixed with other bread, all are Asur b'Hana'ah;
R. Eliezer says, he takes the amount he benefited and throws it in the sea, then all the loaves are permitted.
Chachamim: One cannot redeem idolatry!
Conclusion: R. Yosi permits Zeh v'Zeh Gorem even regarding idolatry. He tells Chachamim 'if you forbid Zeh v'Zeh Gorem, you should forbid vegetables even in winter.' Chachamim permit, like Rav Mari taught.
(Rav Yehudah): The Halachah follows R. Yosi.
A case occurred, and Rav Yosef ruled like R. Yosi.
68a (Beraisa): If Se'or of Terumah and of Chulin fell into a dough, and each was enough to ferment it by itself, and they fermented it, it is forbidden;
R. Shimon permits it.
(R. Yochanan): They argue in a case that the Isur was detrimental (to the taste) from the beginning.
Rif and Rosh (Avodah Zarah 21b and 3:8): The Halachah follows R. Yosi, who permits Zeh v'Zeh Gorem.
Ran (DH v'Asikna): At first, we thought that Chachamim permit Zeh v'Zeh Gorem. We understood why they forbid planting vegetables under an Asherah in summer, for we initially understood that Zeh v'Zeh Gorem is permitted when the causes mix, like land and falling leaves, but not when they are separate, e.g. shade and land. We conclude that the lenient opinion permits Zeh v'Zeh Gorem even when they are separate. Also the Rambam says so. However, the Ramban says that also the conclusion forbids Zeh v'Zeh Gorem when they are separate. Perhaps even b'Di'eved it is forbidden.
Gra (YD 142:29): The Ramban explains that in the conclusion, R. Yosi addresses Chachamim who forbid to grind up idolatry and throw the dust to the wind. (However, the argument about shade of an Asherah does not depend on Zeh v'Zeh Gorem, for it does not mix with the Heter.)
Ran (21a DH v'Hivrich): Why did the Gemara infer that R. Yosi (who forbids vegetables even in winter) forbids Zeh v'Zeh Gorem? Even the lenient opinion permits Zeh v'Zeh Gorem only b'Di'eved! Rather, all forbid an overt act, e.g. planting a nut of Orlah, for he is Mevatel Isur l'Chatchilah. The Hana'ah (of shade) comes automatically to vegetables. This is not like Mevatel Isur l'Chatchilah, and one who permits Zeh v'Zeh Gorem permits it l'Chatchilah.
Hagahos Ashri: It is permitted even regarding Avodah Zarah, and even if there is more Isur than Heter, like the Rashbam says.
Rambam (Hilchos Ma'achalos Asuros 16:13): If Se'or of Kilai ha'Kerem and of Terumah fell into a dough, and there was not enough of either one to ferment it, but together there is enough to ferment it, the dough is forbidden to Yisre'elim and permitted to Kohanim. The same applies if spices of Kilai ha'Kerem and of Terumah fell into a pot, and there was not enough of either one to season it, but together there is enough to season it, for it was seasoned by something forbidden to Yisre'elim and permitted to Kohanim.
Rambam (16): If Se'or of Terumah or of Kilai ha'Kerem fell into a fermented dough, if it was enough to ferment it had the dough been unfermented, it is all forbidden. If not, if there is the proper Shi'ur of Heter, it is Batel. The same applies if spices of Terumah or of Orlah fell into a seasoned dish.
Rebuttal (Ra'avad): Extra Se'or does not ruin a dough, for it makes it (Se'or, and) able to ferment other doughs. A seasoned dish is different, for we do not save an overseasoned dish to season other dishes!
Mordechai (Chulin 733, cited in Beis Yosef YD Sof Siman 87 DH Kasav): A case occurred in which much milk was curdled in a Keivah (milk found in a stomach), and later a little of the small intestines was found with the Keivah. R. Baruch permitted because it is not normal that the Keivah is totally Asur (due to absorption from the intestines), i.e. the clear (milk of the Keivah). Usually, there is also some congealed (milk, which is Pirshah (a mere secretion), and is permitted). Sometimes the congealed is the majority. Therefore, this is Zeh v'Zeh Gorem, which is permitted, just like Se'or of Terumah and of Chulin. R. Shimon and Chachamim argue about this. If the Isur could not curdle by itself, all permit. Chachamim say so explicitly in Avodah Zarah. Shmuel rules like R. Yosi, who permits Zeh v'Zeh Gorem.
Tosfos (68b DH l'Rebbi): Why didn't R. Yochanan say that R. Shimon and Chachamim argue about Zeh v'Zeh Gorem, like on 49a? That is only when there is not enough Isur (to ferment) by itself. When there is enough, all forbid.
Shulchan Aruch (YD 87:11): If one was curdled milk in the skin of the stomach of a Neveilah, Tereifah or Tamei animal, this forbids any amount.
Rema: This is because if something that is itself forbidden curdled, it is not Batel even in 1000 (parts of Heter). This is only if there was no other Ma'amid (curdling agent). If there was also a permitted Ma'amid, this is Zeh v'Zeh Gorem, and it is permitted if there is 60 times as much Heter as Isur.
Question (Taz 13): It seems that the Rema permits even when there was enough Isur to curdle by itself. Abaye says that it is Zeh v'Zeh Gorem only when there was not enough Isur to curdle by itself! Then R. Eliezer and Chachamim argue, and we permit. When there was enough Isur, all forbid! Tosfos (68b DH l'Rebbi) says so. We must say that here we know that there was not enough Isur to curdle by itself. Why did the Mordechai say that if the Isur could not curdle by itself, all permit? He must mean that R. Shimon and his Chachamim agree, but indeed R. Eliezer and his Chachamim argue about this.
Shach (36): The Rema permits only when there was not enough Isur to curdle by itself. This is clear from the Mordechai, who brought a proof from the Beraisa about Se'or. The Tana'im argue when there is enough Isur to ferment by itself, but if not, all permit. Also Tosfos says so. However, perhaps fermenting is different, for it gives real taste (Chulin 99b). It seems that the Mordechai does not distinguish like this. In practice, this requires investigation.
Be'er ha'Golah (): Also the Rambam (16:16) forbids only when there is enough Isur by itself.
Aruch ha'Shulchan (42): Even though the Rema connotes that he permits even when there is enough Isur by itself, l'Halachah we permit only when there is not. However, regarding Keivah, since the Rif and Rambam permit even the clear milk (also it is Pirshah), perhaps we permit in any case. This requires investigation.