• Concern for relations בדיעבד, an imprisoned woman

Ravina answers the contradiction posed on the previous Daf, that our Mishnah only prohibits leaving an animal with an idolator לכתחילה – initially, because we are concerned he may have relations with it, whereas the Baraisa, which permits buying an עכו"ם’s animal for a korban, is בדיעבד – after the fact, i.e., we are not concerned such relations actually took place. Ravina attempts to prove this distinction from a contradiction between our Mishnah, which prohibits a woman’s seclusion with an עכו"ם because he may have relations with her, and another Mishnah which states: האשה שנחבשה בידי עובדי כוכבים – a woman who was imprisoned in the hands of idolators, ע"י ממון מותרת לבעלה – if it was because of money she owed them, she is permitted to her husband, and we are not concerned she had relations with them. This apparently proves that although seclusion is prohibited לכתחילה, בדיעבד we are not even concerned that she may have been forcibly violated (prohibiting a Kohen’s wife to her husband). However, this proof is rejected, because specifically here, when she was imprisoned for money, מתיירא משום הפסד ממונו – he is afraid to violate her because of the risk of losing his money. This is proven from the סיפא, which teaches that if she was imprisoned for נפשות – a capital crime, she is forbidden to her husband, and we are concerned she had relations with her jailer.

• 2. Machlokes about a פרה אדומה purchased from an עכו"ם

Rebbe Pedas answers that Tannaim argue if we are concerned for an עכו"ם having relations with animals, and our Mishnah is Rebbe Eliezer, who is concerned, and the Baraisa (which permits buying a korban from them) is the Rabbonon, who are not concerned. In a Mishnah about פרה אדומה, Rebbe Eliezer says: אינה נקחת מן העובדי כוכבים – it cannot be purchased from idolators, but the Chochomim permit it. They presumably argue whether we are concerned that the animal was disqualified through רביעה. It cannot be that Rebbe Eliezer’s concern is merely that the idolator placed some small burden on it, because משום ניחא פורתא לא מפסיד טובא – for a bit of resting he would not risk losing so much money by disqualifying the פרה אדומה. In contrast, we are still concerned for רביעה, because יצרו תוקפו – his desire seizes him and he may have relations with the animal anyway, despite the great loss. Rebbe Eliezer’s ruling is also not limited to פרה אדומה, based on a derashah requiring a פרה אדומה to be purchased from a Jew, because Rebbe Eliezer explicitly disqualifies animals purchased from idolators for any korban.

• Is a parah adumah קדשי מזבח or קדשי בדק הבית?

All Tannaim would agree that a פרה אדומה would be disqualified if רביעה did take place. The Gemara suggests that this proves a פרה אדומה is "קדשי מזבח", i.e., it is considered a korban (although it is not sacrificed on the מזבח). Had it only been "קדשי בדק הבית", i.e., possessing only monetary kedushah, it would not be disqualified through רביעה!? The Gemara responds that it actually is only קדשי בדק הבית (and redeemable without a מום), but is still disqualified through רביעה, because חטאת קרייה רחמנא – the Torah calls it a chatas, comparing it to a חטאת for this law. However, the Gemara objects that if so, then יוצא דופן – [an animal which] came out of its mother “through the wall” (i.e., an unnatural birth) should also be disqualified (like a חטאת), yet Rebbe Shimon considers it valid!? Therefore, the Gemara explains differently why רביעה disqualifies a parah adumah: הואיל ומום פוסל בה – since a blemish disqualifies it, דבר ערוה וע"ז נמי פוסל בה – עריות and idolatry also disqualify it. This is because the passuk says: כי משחתם בהם מום בם – for their corruption is in them; their blemish is in them, and Rebbe Yishmael taught that the word "השחתה" connotes עריות and עבודה זרה.