Clarification: The Gemara currently thinks that it is speaking about vessels that were there initially, and that they are also arguing where one of the doors is opened regarding the vessels that were initially there.

Implied Question: And when the Tana said earlier that 'If one of the doors is opened it is Tamei and the others are Tahor, and Beis Shamai does not argue?

Answer: That speaks by vessels which were placed there afterwards.

Question: Why do they then argue about where he thought ... ? Why not where one of the doors was opened and regarding vessels that were there initially?

Answer: The Tana says 'Chashav' to teach us a Chidush according to Beis Hillel, that they argue even a mere thought helps to save all the other doors.

Question: According to Beis Hillel however, who holds of 'B'reirah', what is the case regarding where the Meis is lying in the house, which has many doors that are all Tamei?

Question (cont.): Why do we not say that when they eventually take it out of one of the doors, it is retroactively clarified that this was the door through which the Meis was destined to leave?

Answer #1: It speaks where they took it out via a newly made doorway, where 'B'reirah' does not apply ...

Answer #2: Or where the Meis remained in its place.

Question: Why is it not 'Bateil be'Rov'?

Answer #1: Because animals, which are Chashuv, cannot become Bateil.

Answer #2: Alternatively, it is a Davar which will become permitted after Yom-Tov, and 'Anything that will automatically become permitted, is not subject to Bitul.

Question: Since when do we rely le'Kula by a 'Davar she'Yesh lo Matirin'?

Answer: Since two birds remained in their original location, in such a case we definitely rely le'Kula.

Explanation #1: He picks the better Manah of the two, and stipulates 'If this one is the Ma'aser coin, that is fine, whereas if the other one is the Ma'aser coin, then the Kedushah will be transferred on to this one'.

Question: We learned in Perek ha'Zahav (Bava Metzi'a, Daf 45.) that one cannot transfer Kedushah of silver coins on silver coins, nor copper ones on copper ones?

Explanation #2: It therefore speaks where one first transfers the Manah of Ma'aser on to copper P'rutos, and the copper P'rutos on to the better Manah.

Clarification: Because we assume that he took the money of Ma'aser Sheini, and that this is different money.

Question: We only say the S'vara of 'Ani Omer' to be lenient by a de'Rabbanan, as we learned in Pesachim (Daf 10.), where the Gemara states 'T'rumah is different, since it is mi'de'Rabbanan', which is why we say "she'Ani Omer"?

Answer: Since nobody places Chulin next to Ma'aser, we are justified in saying 'she'Ani Omer' le'Kula, because we can safely assume that he forgot having taken them from their place and later put those in their place.