He may say to him - to the one who was robbed.

That which is yours is before you - as it is, in its current state, since it is damage that is not discernible.

His offering - [from the verse] "if your offering is a burnt offering." [Leviticus 1:3]

But not stolen - since a stolen [animal] cannot come "to be accepted" [Leviticus 1:3]. [At this point] we assume that he stole an unconsecrated animal and brought it [as an offering]. [As the gemara continues,] "what are the circumstances? If we say," etc.

And according to your reasoning - under your assumption that he stole [an] unconsecrated [animal] and consecrated it.

That which is taught - regarding a zav.

His bedding - [from the verse] "those persons who touch his bedding" [Leviticus 15:5]. By scriptural decree, stolen bedding is excluded, in that it cannot become a primary source of impurity that is able to render people impure.

Is there anyone who says that - any one of those amoraim [that would say that] a change does not cause acquisition? Aren't they only disagreeing as to whether despair [can effect acquisition]?

Who robbed another of an offering - which his fellow consecrated. Actually [the discussion involves a case where the animal was stolen] before despair. It is necessary to teach us that [such an animal] is not considered a [valid] burnt offering to constitute acceptance at all, even for the original owners, and even though there was no despair. Another explanation: one who stole his fellow's sacrifice does not acquire it even after despair, since sacrifices cannot be stolen, since "anywhere that it is, it is in the treasure house of the Merciful One" [Rosh Hashanah 6a:9].

Thought renders them [susceptible to become] ritually impure - a homeowner would not typically sell them, but would turn them into bedding and side tables and covers. Once he mentally designates them as something fit for use without any further labor, they immediately become susceptible to ritual impurity.

Belonging to a leatherworker - who typically sells them, his thought does not render them [susceptible to becoming] ritually impure, since he [is likely to] change his mind and sell them -- the purchaser would make them into shoes; their work in that respect is incomplete.

Of a thief -- his thought renders them susceptible to ritual impurity - since he acquired them through the despair [of the original owner]. [The tanna kamma of the mishna] holds that the default assumption regarding theft is that the owners have despaired, since they don't know against whom to bring a claim.

Of a robber -- his thought does not render them susceptible to ritual impurity - even if he mentally designated them as something that requires no further labor, such as coverings for bundles, horses or mules, such as those which are made from bearskins. The reason being, that the default assumption regarding robbery is that there is no despair, since he knows who took it and can sue him in court.

The matters are reversed - the default assumption regarding robbery is that there is despair -- because he robbed him of it right before his eyes, he must be a powerful person. But the default assumption regarding theft is that there is no despair, since he believes that the thief will be found.

Where he trimmed them - DROMIR in a foreign language. Because there are two factors: a physical change and despair. Otherwise, just despair on its own does not effect acquisition.

But is it not the case that they taught this here with regard to a table top - where he mentally designated them as a leather table top -- a side table -- which one eats upon, which is similar to a table.

And a table top does not require trimming - it would also be susceptible to ritual impurity without trimming, since it is fit for purpose, since trimming is only done to beautify it. We know we are dealing with a table top, since it is taught nearby to [the current mishna under discussion] in Tractate Kelim "whenever no act is lacking," etc. [Kelim 26:7].

Except for a table top - even though it lacks trimming, thought renders it susceptible to ritual impurity.

Abrazin - this is a table top in Aramaic. But despair on its own would not effect acquisition.

As initially it was a beam - before it was installed in the building.

And now it is a telala - a roof, once it is installed in the large building and a ceiling of boards and a second story are put on top of it.

With regard to a marish - a beam. [This is one of] a series of ordinances from Tractate Gittin. [Gittin 55a:4]