Avodah Zarah Daf 27 עבודה זרח דַף 27

In a Baraisa, Rebbe Yehudah says that a Yisroel may circumcise a כותי, but a כותי may not circumcise a Yisroel, because they circumcise for the sake of their idol on הר גריזים, which is invalid. Rebbe Yose disagrees: וכי היכן מצינו מילה מן התורה לשמה – where do we find in the Torah that מילה must be performed for its own sake (i.e., for the mitzvah)? Rather, a כותי can circumcise a Yisroel. Rav Chisda explains that Rebbe Yehudah does require a מילה to be performed לשמה because he darshens לה' המול – for Hashem, to be circumcised. Rebbe Yose darshens the doubled phrase "המול ימול" to validate מילה regardless of one’s intent. In another Baraisa, Rebbe Yehudah HaNasi says that מילה performed by an idolator is invalid, because the passuk says: ואתה את בריתי תשמור – and you shall guard my covenant (you, and your offspring after you, etc.). Rav also says this source, but Rebbe Yochanan says the source is "המול ימול" – circumcised, he shall be circumcised, teaching that only those who are themselves circumcised may perform a מילה. The Gemara eventually says that the difference is if a woman may circumcise.

The next Mishnah states: מתרפאין מהן ריפוי ממון – we may be healed by them, a monetary healing, אבל לא ריפוי נפשות – but not healing of the "נפש". This cannot mean to distinguish between non-life-threatening conditions and life-threatening conditions, because Rav Yehudah said: אפילו ריבדא דכוסילתא לא מתסינן מינייהו – even for the puncture from bloodletting (which is only painful), we are not treated by them!? Rather, the permitted "ריפוי ממון" refers to healing one’s animal, and the prohibited "ריפוי נפשות" refers to healing oneself. Mar Ukva says that if a pagan doctor told a Jew: סם פלוני יפה לו סם פלוני רע לו – “Such a potion is beneficial to him, or such a potion is harmful to him,” it is permitted to take his advice. The gentile suspects that the Jew, who is declining treatment but only asking advice, will ask someone else and is merely testing his truthfulness. [At the end of the Daf, Rebbe Yochanan permits being treated by pagan doctors for conditions which are not life-threatening]

Rebbe Yochanan said: ספק חי ספק מת – a patient who may live and may die if he is not treated, may not receive treatment from a pagan doctor, because it is likely the doctor will kill him. ודאי מת – But if he will definitely die if left untreated, מתרפאין מהן – we may be healed by them. The Gemara asks, האיכא חיי שעה – but there is short-term life that he risks by receiving the doctor’s treatment!? It answers: לחיי שעה לא חיישינן – we are unconcerned about short-term life where risking it facilitates possible long-term recovery. This can be demonstrated from the מצורעים, who reasoned that if they would enter the besieged city, they would die of starvation, so they went to the besieging army camp who might let them live, although this risked being killed sooner. This principle is challenged from a Baraisa which prohibits being healed by a מין, even someone with only חיי שעה. Ben Dama was once bitten by a snake, and his uncle Rebbe Yishmael prohibited him from being healed by a מין. Ben Dama died while attempting to prove from the Torah that it was permitted, and Rebbe Yishmael declared him fortunate for dying in purity without transgressing the Sages’ words. The Gemara answers: שאני מינות דמשכא – heresy is different, because it draws one after it. All healing of a מין is prohibited, because of the risk of being drawn after them.