1) PROPER REPENTANCE
QUESTION: The Gemara relates an incident about a butcher who was caught selling non-kosher meat. Although he showed signs of penitence by growing his hair and nails long, Rava said that we cannot trust that those signs of remorse are sincere; he might be trying to fool us into thinking that he has repented. In order for us to know that he has done Teshuvah fully and wholeheartedly, he must go to a place where he is not known and voluntarily return an expensive Aveidah (lost object) there, or dispose of valuable Tereifah meat. Once he is willing to forgo such monetary gains, we can be sure that he has repented fully.
The CHIDUSHEI HA'RAN asks why should we be so strict with the Teshuvah of the butcher? The Gemara in Bechoros (30b) cites a Beraisa which teaches that when a person is suspected of transgressing the laws of Shemitah or Taharah, or of not treating Terumah with the proper Kedushah, if he accepts upon himself in the presence of three Talmidei Chachamim to observe the Halachos, then he is trusted thereafter. We do not suspect him of trying to fool us. Why, then, in the case of the butcher, do we suspect him of trying to fool us?
ANSWERS:
(a) The RAN cites the TESHUVOS HA'RA'VAD who explains that the butcher in this incident intentionally sold Tereifos to others. In the Gemara in Bechoros, the people were simply ignorant Amei ha'Aretz who were not careful about certain Halachos. They did not intentionally conspire to fool other people into thinking that something was kosher when it was not.
The Ran rejects this answer based on an inference from the Gemara in Bechoros. The Gemara there implies that even a person who intentionally feeds Terumah to others can do Teshuvah by accepting to follow the Halachah in the presence of three Talmidei Chachamim.
(b) The Ran cites the RAMBAN who answers that the Chachamim were more strict with the butcher because he was entrusted with a public appointment and everyone relied on him. By taking advantage of his position, he betrayed the loyalty of the people, and thus he must do more in order to fully repent.
(c) RABEINU DAVID, a Talmid of the Ramban, adds that the Chachamim were more strict with this butcher because his Aveirah caused him to lose his job. Consequently, there was more of a reason to suspect that he was demonstrating outward signs of repentance merely in order to regain his job and income, and not out of sincere remorse for his actions.

25b----------------------------------------25b

2) "MAFRICHEI YONIM"
QUESTIONS: The Gemara cites two explanations for the words in the Mishnah, "Mafrichei Yonim." Some say that it means "bird racers," and others say that it refers to a technique by which one attracts birds from the dovecotes of others and takes them as his own. The Gemara (25b) cites a Beraisa as proof for the former opinion. The Beraisa says that Mafrichei Yonim are people who are "Mamrin Es ha'Yonim." RASHI explains that this means people who incite the birds to fight against each other.
The Beraisa continues and says that the same Halachos apply to people who do this act with domesticated or wild animals. Such people are considered to have repented fully when "they break their Pegamim." Rashi explains that these "Pegamim" are wooden sticks with which the Mafrichei Yonim rouse the birds. The Beraisa adds that they must fully regret their past actions and not practice their old profession "even in the desert." The Gemara deduces from the Beraisa that the act of "Mafrichei Yonim" does not refer to a technique of attracting the birds of others, because this cannot be done with domesticated or wild animals. The Gemara answers that it can be done even with domesticated or wild animals by using a Shor ha'Bar to lure the other animal.
Rashi explains that when the Gemara says that the proper repentance of those who were Mafrichei Yonim involves refraining from practicing this profession even in the desert, it is not the Beraisa speaking. Rather, those words are interjected by the opinion which translates the words "Mafrichei Yonim" to mean "bird thieves." They must refrain from practicing their profession even in the desert, where all birds are Hefker. According to the other opinion, which says that the words "Mafrichei Yonim" refer to bird racers, it makes no difference where the birds are raced; the act is still an improper one, regardless of whether one races birds in the desert or in residential areas, and thus the Beraisa would not have said "even in the desert." This is consistent with the Gemara's conclusion that the Beraisa can be understood even according to the opinion that "Mafrichei Yonim" means bird thieves.
A number of questions may be asked on Rashi's explanation.
1. Why does Rashi translate "Mamrin Es ha'Yonim" as people who incite birds to fight with each other? This does not conform with either of the explanations given for "Mafrichei Yonim"!
2. According to the opinion that Mafrichei Yonim are bird thieves, which is the opinion expressed by the Beraisa according to Rashi, what is the meaning of the Beraisa's statement that in order to repent, they must break the sticks with which they rouse the birds? Since they are not racing the birds, why would they have to rouse them with sticks? The thieves simply attract the birds to come to them!
3. Why does the Gemara assume that it is impossible to attract animals the same way that one attracts birds? Perhaps a person can lure animals by making particular sounds just as he can lure birds to come to him!
ANSWERS: The Rishonim offer several ways to explain this Beraisa.
(a) The words of RASHI on the Rif seem to clarify Rashi's intention here. Rashi explains that according to both explanations, the person incites the birds to fight with each other. Those who explain that "Mafrichei Yonim" refers to bird racers will explain that either one of the racers can win -- by having his birds reach the designated destination first, or by having his birds kill or disable the competitor's birds. Those who explain that "Mafrichei Yonim" refers to bird thieves will explain that the thief has a bird which incites the birds of a neighbor's dovecote, chasing them from their home towards the thief's dovecote (see YAD RAMAH and ME'IRI).
The ME'IRI explains that the "Pegamim" are used to excite the victim-birds so that they leave their nests, and after they have left the nests it is possible to lure them through the trained bird's chirping. The YAD RAMAH explains that the trained bird was tied to a string that was tied to a block of wood so that it not fly away; that block of wood is the "Pegam" to which the Beraisa refers.
According to Rashi, the Gemara's question on the opinion that says that "Mafrichei Yonim" refers to bird thieves is based on the fact that the thief uses a bird to attract the other birds. An animal thief would use an animal to attract the other animals. The Gemara's question is how can a person raise a domesticated animal to attract other domesticated or wild animals that are grazing in public areas? If the domesticated animal goes out into the wild, it will be chased away by the wild animals there and will not attract any animals! The Gemara answers that the Shor ha'Bar, although it is domesticated, has a natural tendency towards aggressiveness and it will not be frightened by the animals of the wild.
(b) The ARUCH (cited in the margin of the Gemara and by Rashi on the Rif) explains that "Mamrin" means that the person either trains ("Moreh") birds to race faster than other birds, or teaches the birds of others to follow him, such as by whistling. The "Pegamim," according to the Aruch, are the traps which the person uses to capture the birds that he races or that he steals. The Gemara's question, according to the Aruch, may be understood as the Me'iri explains. A person cannot attract tamed animals by whistling and clacking at them with sticks; he can attract only wild animals that way. Why, then, does the Beraisa mention one who uses this profession on domesticated animals? The Gemara answers that the Shor ha'Bar, although it is domesticated, can be lured in this manner, since by nature it is less domesticated than other animals. The Yad Ramah gives a similar explanation for why only a Shor ha'Bar can be lured.