- Maaser sheni worth less than a perutah is בטל ברוב
On the previous Daf, Chizkiyah taught that maaser sheni worth less than a perutah can be redeemed with money previously used for chilul maaser sheni, because we assume not all the money was used. This is challenged from a Mishnah, which implies that maaser is בטיל ברובא – nullified in a simple majority, which is also proven from a Baraisa. But according to Chizkiyah, that even less than a perutah’s worth of maaser can be redeemed, it should be a דבר שיש לו מתירין – an item which can be permitted without nullification, which is never nullified in a mixture!? The Gemara answers that the case is where he had not previously redeemed any maaser. He cannot bring a half-perutah’s worth of maaser and redeem them jointly, because דאורייתא ודרבנן לא מצטרפי – Biblical and Rabbinical [maaser] cannot combine for chilul (and the maaser in the mixture is Biblically nullified, and only requires chilul Rabbinically). Redeeming one-and-a-half perutah’s worth of maaser on two פרוטות would not help, because the second perutah lacks a full perutah’s worth of Biblical maaser to redeem. Although he could bring a larger coin, such as an איסר, and redeem less than its value of maaser, and redeem the mixed maaser with its remainder, we do not allow it, lest he come to use two פרוטות. Another answer is offered on amud beis.
- Maaser which entered and left Yerushalayim (i.e., walls fell) is also בטל ברוב
The Baraisa quoted above taught a second case of maaser which is nullified in a mixture of majority chullin, because it cannot be redeemed: ושנכנס לירושלים ויצא – [maaser] which entered Yerushalayim and left, and cannot be eaten or redeemed. The Gemara asks that he can simply bring the entire mixture back into Yerushalayim and eat it there, and initially answers that the maaser became tamei, and forbidden in consumption. This is rejected, because maaser which became tamei may be redeemed, even in Yerushalayim itself. The Gemara ultimately answers that it is discussing maaser which is tahor (which cannot be redeemed), and when the Baraisa says it “left” Yerushalayim, it means: דנפול מחיצות – that the walls of Yerushalayim fell, and it cannot be eaten inside Yerushalayim. Although Rava taught: מחיצה לאכול דאורייתא – the law of the wall of Yerushalayim for eating (i.e., requiring maaser to be eaten within its walls) is Biblical, מחיצות לקלוט דרבנן – but the law of the walls to contain [maaser] that it cannot be redeemed after entering Yerushalayim is Rabbinical, and this Rabbinical law applies even when the walls of Yerushalayim fell.
- If the requirement of a שוה פרוטה for redemption refers to the maaser or the חומש
A Baraisa teaches that the Torah used the word "ממעשרו" – “of” his maaser with regard to redemption, implying ולא כל מעשרו – that not all of his maaser can be redeemed: פרט למעשר שני שאין בו שוה פרוטה – this excludes maaser worth less than a perutah from redemption. Rebbe Ami explains (as does Rebbe Yochanan): אין בו – the case is that it (i.e., the maaser itself) does not have a perutah’s value. Rav Assi says (as does Reish Lakish): אין בחומשו – its fifth does not have a perutah’s value (i.e., even if the maaser is worth a perutah, it cannot be redeemed unless it is worth fourth פרוטות, which would have a חומש of a perutah). A Baraisa’s language appears to contradict the first opinion, and the Gemara concludes that it is a difficulty.