1) A BLESSING ON FORBIDDEN FOOD
OPINIONS: Abaye (93b) lists several Tana'im who maintain that a stolen object remains in the possession of the original owner even when the thief makes a Shinuy to the object. One of those Tana'im is Rebbi Eliezer ben Yakov. Rebbi Eliezer ben Yaakov said that when one steals a Se'ah of wheat and he grinds, kneads, bakes, and even separates Chalah from it, he may not recite a blessing over the b read when he eats it. The blessing would not be a praise to Hash-m but rather a curse. The verse says about such a person, "And the robber blesses himself about having blasphemed Hash-m" (Tehilim 10:3), which Rebbi Eliezer ben Yakov interprets to mean, "And the robber who makes a blessing [on food that he stole] has blasphemed Hash-m." Abaye understands from this statement that Rebbi Eliezer ben Yaakov maintains that the thief does not acquire the stolen wheat through the Shinuy, because if he does acquire it through the Shinuy it would now be his wheat and his blessing should be valid. (Some explain that the blessing to which Rebbi Eliezer ben Yakov refers is the blessing for the Mitzvah of separating Chalah, while others say that it refers to the blessing recited before one eats the bread. See SHITAH MEKUBETZES here and TESHUVOS AFRAKASTA D'ANYA 1:148.)
Rava replies that Abaye's proof is refutable. Perhaps Rebbi Eliezer ben Yakov maintains that a thief does acquire the stolen object with a Shinuy. The reason why Rebbi Eliezer ben Yaakov said that the thief's blessing is like a curse is that the object for which he makes the blessing is a stolen object, and thus his blessing is a "Mitzvah ha'Ba'ah b'Aveirah."
The Gemara here may be the source for the dispute among the Poskim with regard to whether one recites a blessing when he eats forbidden food.
(a) The RAMBAM (Hilchos Berachos 1:19) writes that one who eats forbidden food recites no blessing over it, before or after eating, whether he eats it deliberately or inadvertently.
(b) The RA'AVAD cites the Mishnah in Berachos (45a) which states that when one eats Tevel (produce from which Terumos and Ma'aseros have not been separated) or other forbidden foods, he may not join others to make a Zimun for Birkas ha'Mazon. The Mishnah implies that although he cannot join the Zimun, he is obligated to recite Birkas ha'Mazon.
The ROSH (Berachos 7:2) cites support for the Ra'avad's opinion from the opinion of Rebbi Eliezer ben Yakov in the Gemara here, who says that one who recites a blessing over stolen bread is considered as though he curses Hash-m. This implies that he is obligated to recite the blessing, but the blessing which he recites is considered a curse and not a blessing. The MA'ADANEI YOM TOV (#40) explains that the Rosh makes this inference from the Gemara's terminology. The Gemara does not say that the thief "may not recite a blessing." Rather, it says that he "does not bless but rather curses." This implies that the blessing which he is required to recite is considered a curse.
The KESEF MISHNEH points out that the Girsa of the Gemara according to the Rosh is slightly different from the Girsa which appears in our text. Our text reads, "How can he recite a blessing? He does not bless but rather curses Him!" The Rosh's text omits the words, "How can he recite a blessing?" Accordingly, the Kesef Mishneh asserts that the Girsa of the Gemara as it appears in our text certainly supports the Rambam's opinion. The Gemara's question, "How can he recite a blessing?" expresses astonishment at the thief's recitation of a blessing in the first place. The Gemar means that if a thief would recite a blessing on such an item, it would be nothing more than a curse.
The Kesef Mishneh adds that even according to the Rosh's text, the Gemara does not necessarily provide support for the Ra'avad's opinion. The Gemara may be understood as saying that if one would recite a blessing on the stolen food, he in fact would not be blessing Hash-m but rather cursing Him. Accordingly, the conclusion of the Gemara is that one should not recite a blessing.
HALACHAH: The SHULCHAN ARUCH (OC 196:1) rules that when one eats a forbidden food, he does not recite a blessing either before or after he eats, even if the food is forbidden only mid'Rabanan. The MISHNAH BERURAH (196:4) cites the TAZ and other Acharonim who write that if one eats the food inadvertently and only afterwards realizes that it is forbidden, he may recite the Berachah Acharonah, since the act of eating is not considered a curse (as he did the act inadvertently). Even in such a case, however, one should not join a Zimun after he has eaten such food. (D. Bloom)

94b----------------------------------------94b

2) THE GEMARA FOLLOWS THE VIEW OF RAMI BAR CHAMA
QUESTION: The Beraisa states that the victim of a theft may not accept his stolen object when a thief returns it together with the profit he made through his transgression. The victim of Ribis may not accept from the creditor the profit which the creditor made by charging interest on the loan. Rebbi Yochanan explains that this teaching was stated in the days of Rebbi, as related in another Beraisa. The Beraisa relates that there was a man who sought to repent but his wife said to him, "Empty one! If you do Teshuvah than even the belt you are wearing will not be yours!" He was thereby deterred from doing Teshuvah. As a result, the Chachamim declared that one may not receive what thieves (or creditors who loan money with Ribis) return.
The Gemara questions this from another Beraisa which states that when a man dies and leaves to his sons money which he earned through the prohibition of Ribis, the sons are not obligated to return it to the borrowers. The Gemara infers from here that only the sons do not need to return it, but if the father was alive he would be obligated to return the Ribis. This Beraisa seems to contradict the first Beraisa which says that the lender's returns are not accepted.
RASHI (DH Ein Chayavim) explains that the reason why the heirs are not obligated to return the Ribis money which they inherited is that the Torah commands a person to return money acquired unlawfully only when he is the one who stole it. Since the heirs did not steal or charge interest, they do not have to return anything to the victim of their father's unlawful conduct. The Ribis money becomes their property because of the principle, "Reshus Yoresh k'Reshus Loke'ach Dami" -- "the domain of an heir is like the domain of a buyer." Rashi (111b, DH Reshus) explains that this means that when children inherit from their father, the inheritance is considered as though it enters a different domain (and undergoes a "Shinuy Reshus") from that of the father. Therefore, if the victim of the theft or Ribis had Ye'ush, the orphans acquire the object through the combination of Ye'ush and Shinuy Reshus.
Rashi's explanation of the Beraisa based on the principle of "Reshus Yoresh k'Reshus Loke'ach Dami" is not consistent with the Halachah. The Gemara later (111b) says that this principle is only the opinion of Rami bar Chama. Rava there disagrees and maintains that when a man bequeaths a stolen object to his sons after the owner had Ye'ush, the sons do not acquire it through Ye'ush (and inheriting it) alone. The Gemara (112a) says that according to Rava, the reason why sons are not obligated to return the Ribis their father received is that the Torah says, "Take no interest from him... that your brother may live with you" (Vayikra 25:36). The purpose of the Mitzvah to return Ribis is to enable one's brother to be able to live. However, the Torah gives this Mitzvah only to the father who took the Ribis in the first place, but not to his sons. The Halachah follows the view of Rava and not Rami bar Chama (see RAMBAM, Hilchos Gezeilah v'Aveidah 2:1). Why does Rashi explain the Gemara here according to an opinion which the Halachah does not follow? (This question is asked by the MISHNEH L'MELECH, Hilchos Malveh v'Loveh 4:4.)
ANSWER: REBBI AKIVA EIGER (in Chidushim) quotes his son-in-law who answers that Rashi is bothered by the question of TOSFOS (DH Ha). Tosfos questions the Gemara's inference that if the father would be alive he would be obligated to return the Ribis. Why does the Gemara not answer simply that the father indeed would have been obligated to return the Ribis but only "mi'Dinei Shamayim," to fulfill his Heavenly obligation (but Beis Din cannot force him to return it)?
Rebbi Akiva Eiger's son-in-law explains that Rashi maintains that the heirs also are obligated to return the Ribis mi'Dinei Shamayim. Their father essentially bequeathed to them stolen money; just as they are required to honor other financial obligations of their father's estate (even when they do not inherit land; see Kesuvos 91b), they must fulfill requirements of Dinei Shamayim and give back the stolen money, even if they acquired it through Ye'ush and Shinuy Reshus. Accordingly, when the Gemara says that there is a difference between the obligation of the father and that of the son, it must not be referring to requirements of Dinei Shamayim.
However, Rashi maintains that only Rami bar Chama maintains that Ribis is considered theft. The heirs technically acquire that money through Ye'ush and Shinuy Reshus, which is why they are not obligated to return it in Beis Din but must return it mi'Dinei Shamayim. In contrast, according to Rava, Ribis money becomes the possession of the recipient immediately. Only the recipient, and not his heirs, has a Mitzvah to return the Ribis money to the borrower (based on the verse cited by the Gemara on 112a). (See TOSFOS to Bava Metzia 61b, DH Yachin, and Chidushei Rebbi Akiva Eiger here, DH Divrei.) According to Rava, the sons have no obligation to return the money, even mi'Dinei Shamayim. Therefore, Rashi explains that the Gemara here must follow the opinion of Rami bar Chama, because otherwise the question of Tosfos would remain (since the Gemara could have answered that the father must pay mi'Dinei Shamayim, in contrast to the sons who have no obligation to pay mi'Dinei Shamayim according to Rava). (Rebbi Akiva Eiger praises his son-in-law's answer.) (D.Bloom)