We learned in our Mishnah that an Uman and an Aris are not subject to the Din of Chazakah. The Beraisa adds that - their sons do.

In the Seifa, the Beraisa teaches us that a Gazlan does not have a Chazakah either; and the Tana adds that ...

... his son doesn't either, but that ...

... his grandson does.

To reconcile ...

... the Seifa with the Reisha, we cannot establish the Beraisa where the son claims that he inherited the field from his father because then, the same ruling would apply in the Reisha (and the Uman and the Aris would not be believed either).

... the Reisha with the Seifa, we cannot establish it where they claimed that they had purchased the field directly from the owner - because there again the same ruling would apply in the Seifa (and the son of the Gazlan would be believed too).

So we establish the Beraisa when witnesses testify that the owner admitted to their respective fathers that he had sold him the field before his death. Consequently - we can now believe the son of the Uman and the Aris when they claim that their father subsequently bought the field from the owner, since their claim is substantiated by the witnesses.

We do not however, believe the son of the Gazlan, because, as Rav Kahana explained - we presume that the owner only admitted to having sold the field, following the Gazlan's threat to hand over the owner together with the donkey to the governor, and his admission was prompted by fear, thereby rendering it meaningless.

The Gazlan's grandson however, is able to establish a Chazakah should he claim that he bought the animal from his father who was not a Gazlan - because of the principle 'To'anin le'Yoresh', and although we would not have believed his grandfather, we would have believed his father).

According t Rava however, even he would not be able to do so - if his claim was based on his grandfather's ownership.

The alternative version of this ruling (that sometimes even the son of a Gazlan can establish a Chazakah) speaks - where he claims that he received it from his grandfather (the father of the Gazlan), and he is believed with a 'Migu', because he could have claimed to have purchased the donkey from the original owner.

Despite the fact that the Seifa of the Beraisa is speaking where witnesses testify that the owner admitted that he sold the donkey to the Machzik, the Uman and the Aris in the Reisha are not believed - because the Reisha (both of the Reisha and of the Seifa) does not speak in such a case ('li'Tzedadin Katani').

According to Rebbi Yochanan, the Gazlan referred to by the Tana is the one who stole the field on which he is now trying to establish a Chazakah; according to Rav Chisda 'Gazlan' of the Beraisa - refers to someone who is known to murder for the sake of the victim's money.

The difference between the two opinions is that - according to Rebbi Yochanan, the Gazlan can establish a Chazakah on other fields, whereas according to Rav Chisda, he cannot.

The Beraisa rules that an Uman and an Aris who changed their professions - can establish a Chazakah from that moment on.

We learned earlier in a Mishnah that a husband and wife, a father and son cannot establish a Chazakah on each other's property. This Din will change - the moment the man divorces his wife and the son leaves his father's table (e.g. in order to get married).

Ben she'Chilek' is coming to teach us that - once the son leaves his father's table, the relationship that renders them like Apotropsin on each other's property no longer applies, and they are no longer Mochel each other.

We might otherwise have thought that - due to their close relationship, they are always Mochel each other if the one eats the Peiros from the other's field, and cannot therefore establish a Chazakah, ever.

The problem with the Tana's ruling that after a man divorces his wife, they can establish a Chazakah on each other's property is that - seeing as they hate each other, this appears to be obvious.

We answer the current Kashya by establishing the case by a Safek Megureshes - where the husband threw his wife a Get, and we do not know whether it fell closer to her (in which case she is divorced) or closer to him (in which case she is not).

The answer itself is based on a statement of Rebbi Zeira Amar Rebbi Yirmiyah bar Aba Amar Shmuel, who said that - in every case of Safek Megureshes, the man must continue to sustain his wife.

Consequently, we would have thought that - the man therefore designated the field for his wife to eat the Peiros, in order to sustain herself.

We do not say that however - because, having begun to divorce his wife, he clearly hates her, and is unlikely to feed her so liberally, only begrudgingly, bit by bit, as he is forced by Beis-Din to do so.

Rav Nachman quoting Rav Huna, rules that an Uman, an Aris, a husband and wife, and a father and son who claim that they purchased a field are believed (even though we just learned that they cannot establish a Chazakah) - if they bring proof (such as a document of sale or witnesses).

The one exception to the rule is - a Gazlan (or anyone who acquires the field from him) ...

... who is not believed even if he produces a Sh'tar that the owner sold him the field - because of Rav Kahana (whom we cited earlier), who ascribes the proofs to the Gazlan's threats (as we explained there).

The source for this ruling is the Mishnah in Gitin 'Lakach mi'Sikrikun ve'Chazar ve'Lakach mi'Ba'al ha'Bayis, Mekcho Bateil'. The case is - where Reuven bought something from a Sikrikun (a Nochri Gazlan, who would kill people for their money), and then bought it from the owner for whom he even wrote a Sh'tar. The transaction is invalid, because the owner only went through with it out of fear of the Sikrikun ...

... how much more so, in our case where the Nigzal sold it to the Gazlan himself.

In spite of the Mishnah, Rav Huna needs to teach us this in order to preclude from the opinion of Rav - who restricts the Mishnah to where the owner instructed the purchaser in front of the witnesses to go and acquire the object, but not to where he actually wrote him a Sh'tar or received money from the purchaser, in which case he acquires it.

Rav Huna holds like Shmuel, though Shmuel will concede that the purchaser from the Sikrikun ... does acquire the article - if the owner accepts Achrayus.

Rav Bibi concludes in the name of Rav Nachman 'Karka Ein lo, Aval Ma'os Yesh lo', by which he means that - although the Gazlan (in the case of Rav Huna) does not receive the field, he does get his money back ...

... because we might otherwise have thought that we penalize the Gazlan, and he loses his money too.

Rav Bibi confines this to where the witnesses actually saw the Gazlan hand the money to the Nigzal, but not to where they testify that the Nigzal admitted that he received the money or even if they wrote this in the Sh'tar. Rav Nachman rules ...

... in the latter case that the Nigzal is not obligated to return the money on the basis of Rav Kahana's statement (that we cited earlier) - which leads us to assume that no money actually exchanged hands.

... in the former case that he is - because we do not suspect the witnesses of testifying falsely (even out of fear of the Sikrikun).

The case of 'Talyuhu ve'Zavin' is - where Reuven suspends Shimon on a tree until he sells him his field.

Rav Huna holds - 'Talyuhu ve'Zavin, Z'vineih Z'vini' (that if Shimon accedes to his request, the sale is valid).

Rav Nachman holds - that the sale is not valid ...

... as we see from Rav Bibi, who quoted him as saying that the Nigzal must return the money to the Gazlan (a clear sign that Rav Nachman holds 'Talyuhu ve'Zavin, La'av Z'vineih Z'vini').

We refute the suggestion that the reason for this is because in any event, a person only sells his personal effects because he has to, and not because he wants to on the grounds that - whereas that is true of internal (personal) pressure, perhaps external pressure is different (i.e. there he does agree to the sale).

We learn from the Pasuk ...

... "Yakriv oso" that - if someone refuses to bring the Korban that he undertook to bring, Beis-Din beat him until he brings it.

... "li'Retzono" that - he has to want to bring it (and cannot be forced to do so against his will),

We reconcile the two D'rashos by re-interpreting "Yakriv oso" to mean that they beat him until he declares that he is willing to bring it.

This is not a good source however, from which to learn that someone who accedes to external pressure is called 'willing' - because maybe this D'rashah is confined to the realm of Korbanos, where the sinner wants to attain a Kaparah.

Neither can we learn it from the equivalent Halachah by someone who has to be beaten before agreeing to give his wife a Get - because there he only agrees wholeheartedly because it is a Mitzvah to listen to the words of the Chachamim (but who says that it also extends to a sale, which is neither a Kaparah nor a Mitzvah?).

The ultimate source of 'Talyuhu ve'Zavin, Z'vineih Z'vini' is - the S'vara that, due to the pain or fear of the Oneis (in conjunction with the fact that he receives payment for the article), the owner is Makneh it with a full heart.