Reuven, who had sold Shimon all the fields that he had purchased from bei bar Sisin, refused to give Shimon one particular field, even though it was also called 'de'bei bar Sisin', on the grounds that, in spite of its name - he had not purchased it from bei bar Sisin.

Rav Nachman placed that field in the possession of Shimon. Rava disagreed with Rav Nachman, because of the S'vara - 'ha'Motzi me'Chavero alav ha'Re'ayah', in which case, the field ought to remain with the seller, who had a Chazakah on it.

Both Rava and Rav Nachman appear to have switched their opinions from their previous Machlokes (regarding the case of 'Ana be'Shechuni Gava'i Hava'i') - where Rav Nachman placed the disputed property in the domain of the original owner, whereas Rava placed it in the domain of the purchaser.

We resolve the apparent discrepancy according to ...

... Rava, by drawing a distinction between the first case - where it is the purchaser who currently owns the property, whereas in the second case - the property is still under the jurisdiction of the seller.

... Rav Nachman, by going after the purchaser in the case of bei bar Sisin - since even the seller conceded that the field was called 'bei bar Sisin', just as the seller specified, but after the seller in the first case - because the Chazakah is not better than the Sh'tar that he ought to have produced, and which he would have had to substantiate, had the seller demanded it (as indeed, Shimon had to, when Reuven queried it).

In both of the above cases - we rule like Rav Nachman (because the Halachah is generally like him in money-matters).

When Reuven claimed that he was unable to make a Mecha'ah, because he had been overseas ('Ana be'Bati Bera'i Hava'i') during the three years that Shimon was making a Chazakah on his house, Shimon countered - that he had witnesses who had seen him in town for thirty days of each of the years of his Chazakah ...

... which Reuven countered - by claiming that he had been so busy selling his merchandise and buying fresh goods that he had not even been aware that Shimon had been on his land.

Alternatively, we might explain 'Ana be'Bati Bera'i Hava'i' to pertain to a time of war, where it would have been more difficult to get news from one place to another. This interpretation is preferable to the previous one - because if Reuven had merely gone overseas, as we thought originally, then the Chazakah would most likely have taken effect, since just as a Mecha'ah she'Lo be'Fanav tends to spread from one person to another, and from one country to another, so too, will the news that Shimon is making a Chazakah of Reuven's field, in which case, Reuven would have known about Shimon's Chazakah, and he ought to have made a Mecha'ah.

Rava justified Reuven's claim - since it is quite normal for a businessman to be involved in this way.

When Shimon claimed that he had purchased his field from Levi, who claimed that he had purchased it from Reuven - the latter countered that, since Shimon agreed that the field had been his, and that he didn't buy it from him, 'La'av Ba'al Devarim Didi at' (he must return the field to him, and he was not his disputant [i.e. if anyone had a claim against him it was Levi, but not Shimon]).

Shimon did not claim that he had eaten the fruit for three years - because he was claiming with the Sh'tar that he had received from Levi, and not with the power of Chazakah.

Rava justified Reuven's claim, and would have done the same had his claim been based on Chazakah - seeing as it was a Chazakah which did not have the backing of a Ta'anah (since Shimon had not the least proof that the field had belonged to Levi at the time when he bought it from him.

Despite the fact that Reuven's right to the field was based on Shimon's testimony, Rava did not believe the latter on the basis of a 'Migu' (because he could have said that he purchased the field directly from Reuven) - because, since he admitted that the field had originally belonged to Reuven, we apply the principle 'Hoda'as Ba'al-Din ke'Me'ah Eidim Dami', and (since he did not claim that Levi purchased the field from Shimon in his presence) he further admitted that he had not the slightest proof that Levi did indeed buy the field from Shimon, nor did he even have witnesses that he had worked the field for even one day.

When Reuven claimed that Levi, from whom Shimon had purchased his field on which he since made a Chazakah, had stolen the field from him - Shimon countered that he had witnesses who had heard him (Reuven) instruct Levi to sell the field to him.

Reuven justified what he said - with the S'vara that he preferred to make a Din Torah with Shimon than with Levi ('ha'Sheini No'ach li, ha'Rishon Kashah heimenu'.

We learned in a Mishnah in Kesuvos, that if after Reuven claims Shimon's field to be his, it is discovered that he actually signed on the Sh'tar as one of the witnesses, Admon justifies his action on the same basis as Rava in the current case ('ha'Sheini No'ach li ... '). The Chachamim hold - 'Ibad es Zechuso' (that by signing on the Sh'tar, Reuven lost all rights to the field).

We reconcile Rava with the Chachamim, by restricting their ruling to the case there, where Reuven went as far as signing on the Sh'tar (a positive act) - whereas in the case of Rava, where the discrepancy is confined to mere words, they will concede to the S'vara of 'ha'Sheini No'ach li ... '.

In the current case, Shimon's Chazakah does not help him to acquire Reuven's field - because it is a Chazakah she'Ein Imah Ta'anah (as we explained earlier), due to the fact that when Shimon claims (not that he bought the field from him, but) that he purchased it from Levi, whom Reuven knows to be a Ganav, he does not even need to make a Mecha'ah, and he (Reuven) does not therefore lose out for failing to do so.

This is because even if Shimon had a Sh'tar it would be useless in such circumstances, and a Chazakah cannot be more effective than the Sh'tar that it comes to replace.

When Reuven claimed that Levi, from whom Shimon had purchased his field, had stolen it from him, Shimon countered that he had witnesses who had heard him say 'Zavnah Neheli'! - meaning that Reuven actually asked Levi to sell him the field, proving that the field cannot have been his at the time.

When Reuven justified his claim with the words 'Izbun Dina'i', he meant that he preferred to pay a small sum in order to retrieve his field, to spare himself the unpleasantness of having to take Levi to Beis-Din (with all the Machlokes and bitterness that this would involve).

When Reuven challenged Shimon's rights to his field, Shimon replied that he had bought it from Levi and that he had subsequently made a Chazakah. And when Reuven claimed that he had a Sh'tar proving that he had purchased the very same field from Levi four years ago - he countered that when he spoke of a Chazakah, he did not meant just three years, but many years (more than Reuven's four).

Rava justified Shimon's claim - on the grounds that people tend to do that (to refer to a Chazakah, even when they really mean more than three years).

We would otherwise have thought that Shimon's claim ought to be disqualified - because, as we will learn shortly, if a litigant presents an argument that clashes with an earlier one, we follow his first argument and ignore the second one.

Rava then goes on to confine his initial ruling - to where Shimon's Chazakah goes back seven years, three years before the date on Reuven's Sh'tar. Less than that, he would lose the field to Reuven - because Levi's sale to Reuven would then effectively serve as a powerful Mecha'ah, and should have warned Shimon to guard his Sh'tar (until such time as he succeeds in extracting Reuven's Sh'tar from him).

What gives rise to the mistaken theory that Shimon only needs to prove the last three years of his Chazakah, but that he is believed on the previous four - is Rava's phraseology 'Avid Inash de'Kari li'Shenei Tuva Sh'nei Chazakah' (which would seem to be superfluous if Shimon had witnesses for all seven years)

This theory cannot be correct however - because, as we explained earlier, a Chazakah cannot be more effective than the Sh'tar that it comes to replace, and if he had a Sh'tar on only the last three years, he would certainly not acquire the field, in view of Reuven's Sh'tar, which predates his.

And the reason that Rava said 'Avid Inash ... ' is - to teach us that Shimon's second statement does not contradict his first one, and is therefore acceptable.