Question: We could establish the Beraisa more simply! Reuven stole Shimon's field (and did not sell it), and Yehudah claims that it was his. Shimon cannot testify for Reuven, like we explained above.

Answer: We establish the Reisha of the Beraisa regarding a sale for parallel structure with the Seifa, regarding a cow or garment;

The case of a cow or garment must discuss a sale, for the buyer keeps it only if the original owner despaired and there was change of Reshus;

If it were not sold, it would revert to the owner, so Shimon could not testify about it.

Question: Regarding a cow or garment, even if he despairs from getting back the stolen object, he does not despair of getting back his money! (Since he can gain from his testimony, why can he testify?)

Answer: The case is, the thief (Reuven) died;

(Mishnah): If David stole from Moshe and fed the stolen object to his sons, or left it to them and he died, they need not return it to Moshe or pay Moshe (if Moshe despaired before David died (so the sons acquire through despair and change of Reshus), or if they already ate it).

Question: If Reuven died, even if he did not sell it, Shimon can testify for Reuven's heir!

Answer #1: According to the opinion that an heir's Reshus is unlike a buyer's Reshus, the heir would have to return it. This explains why Shimon could not testify.

Question #1: According to the opinion that an heir's Reshus is like a buyer's Reshus, also the heir need not return it, so the question remains;

Question #2 (against Rav Sheshes - Abaye): The Beraisa explains that the difference between the cases is whether there is Achrayus (i.e. the seller must compensate the buyer if the land is taken). According to Rav Sheshes, the difference is whether or not Shimon gets back his property!

Answer #2 (to Question 3:c, 43b - Ravin bar Shmuel): The Beraisa says, if Reuven sold a house or field (even without Achrayus), he cannot testify about it, for this will enable his creditor to collect it;

If he sold a cow or garment, he can testify about it, for a creditor cannot collect it (from the buyer);

This is even if the loan document empowers the creditor to collect 'from the shirt off his back.' These words apply only when the borrower still owns it;

This is even if Reuven made the cow or garment an Apotiki from which the loan will be collected, due to Rava's law;

(Rava): If one made his slave an Apotiki and sold him, the creditor collects him. If an animal was made an Apotiki and it was sold, the creditor does not collect it.

Question: What is the reason?

Answer: A sale of a slave has publicity, but a sale of an animal does not (so the buyer did not know to beware).

Question: We should be concerned lest Reuven gave his creditor a lien on the cow or garment Agav (along with) land (for then the creditor can collect from them, so Reuven gains from his testimony)!

(Rabah): Metaltelim (movable objects) are acquired Agav land (not only absolutely, but also regarding a lien).

(Rav Chisda): This is only if the document says 'this is not Asmachta (an exaggerated, insincere promise) nor a mere form document (from which one copies the text).'

Answer: The case is, he sold a cow or garment right after buying it (surely, he did not borrow in between).

Question: Perhaps he (borrowed before he bought it, and) gave the creditor rights to collect from 'd'Ikni (what I will acquire)'!

Suggestion: This teaches that a stipulation 'd'Ikni' does not enable the creditor to collect the property from one who bought or inherited it from the borrower! (Rather, he collects only as long as the borrower owns it)!

Answer: No, the case is that witnesses say that Reuven never owned land (so we need not worry that he gave a lien Agav land).

Question: Rav Papa taught that even though one who sells land without Achrayus, the buyer has no claim against the seller if it is taken by a creditor, he has a claim if the seller did not own it! (Therefore, Reuven profits from his testimony!)

Answer: The case is, the buyer admits that Reuven owned the cow or garment.

(Rav Zvid): If one sells land without Achrayus, the buyer has no claim against the seller even if the seller did not own it (and the true owner takes it from the buyer);

The seller can say 'this is why I sold it without Achrayus!