(Mishnah): (A Ba'al ha'Bayis is in his house (a Reshus ha'Yachid), an Oni (poor person) is standing outside (in a Reshus ha'Rabim.) If one of them passes an object (on Shabbos) to the other, there are two Yetzi'os (taking something out to a different domain) that the Ba'al ha'Bayis might transgress (depending on the case), four in all (this will be explained), and two Yetzi'os that the Oni might transgress, four in all:
If the Oni takes an object (from outside), sticks his hand inside and places it in the Ba'al ha'Bayis' hand, or if he takes an object from the Ba'al ha'Bayis' hand (inside) and withdraws his hand (outside, holding the object), he is liable (Chayav Misah if he was warned, Chayav Kares if he was Mezid) and the Ba'al ha'Bayis is exempt;
If the Ba'al ha'Bayis takes an object (from inside) and places it in the Oni's hand (outside), or takes an object from the Oni's hand (outside) and takes it inside, he is liable, the Oni is exempt;
If the Oni takes an object (from outside) and sticks it inside, and the Ba'al ha'Bayis takes it from the Oni's hand, or if the Ba'al ha'Bayis puts an object in the Oni's hand (inside) and the Oni withdraws his hand (outside), both of them are exempt;
If the Ba'al ha'Bayis takes an object (from inside) and sticks it outside, and the Oni takes it from his hand, or if the Oni puts an object in the Ba'al ha'Bayis' hand (outside) and the Ba'al ha'Bayis withdraws his hand, both are exempt.
WHICH CASES ARE COUNTED
(Gemara - Mishnah (in Shevu'os)): There are two primary kinds of oaths (of Bituy, that one will or will not do a certain act), there are four in all;
There are two primary Yedi'os ha'Tum'ah (finding out that one transgressed Tum'as Mikdash), four in all;
There are two primary appearances of Tzara'as, four in all;
There are two primary Yetzi'os of Shabbos, four in all.
Question: Why does that Mishnah count only two Yetzi'os that are four [and not the other cases in our Mishnah]?
Answer #1: Our tractate is all about Shabbos, the Mishnah counts Avos (primary Melachos, such as Yetzi'os) and Toldos (those derived from Avos);
Tractate Shevu'os mentions Shabbos only in passing, the Mishnah counts only Avos.
Objection: The Avos are Yetzi'os (taking something from Reshus ha'Yachid to Reshus ha'Rabim, the case mentioned in the Torah, i.e. people were bringing donations for the Mishkan from their tents to Machaneh Levi);
There are only two Yetzi'os (one by the Ba'al ha'Bayis (in (b) above), and one by the Oni (in (a) above) - how can the Mishnah (in Shevu'os) say that there are four in all?!
Suggestion: That Mishnah counts (two) Yetzi'os for which one is liable, and (two) Yetzi'os for which one is exempt (e.g. when the Akirah (uprooting a stationary object) and Hanachah (putting it down to rest) were done by different people).
Rejection: Surely, the Yetzi'os are akin to appearances of Tzara'as [in the same Mishnah];
All four appearances are Tamei - likewise, one is liable for all four Yetzi'os!
Answer #2 (Rav Papa): Our tractate is all about Shabbos, the Mishnah counts cases of Chiyuv and Petur;
Tractate Shevu'os mentions Shabbos only in passing, the Mishnah counts only those of Chiyuv.
Question: One is liable for Yetzi'os - there are only two Yetzi'os, how can the Mishnah say that there are four in all?
Answer: There are two Yetzi'os and two Hachnasos.
Question: The Mishnah only mentions Yetzi'os!
Answer (Rav Ashi): The Tana includes Hachnasos in the term 'Yetzi'os':
(Mishnah): Ha'Motzi (one who is taking something out) from one domain to a different domain is liable.
Explanation: This refers to taking (from Reshus ha'Yachid to Reshus ha'Rabim, and also) from Reshus ha'Rabim to Reshus ha'Yachid, and this is called Hotza'ah!
Question: Why are Hachnasos called Yetzi'os?
Answer: Any uprooting of an object from one place to another is called Hotza'ah.
Support (Ravina): Our Mishnah mentions Yetzi'os, and the first case it explains is Hachnasah!
Answer #3 (Rava): The Mishnah means, there are two domains of Shabbos (Reshus ha'Yachid and Reshus ha'Rabim; our Mishnah counts four prohibitions of transferring between them for a Ba'al ha'Bayis, and four for an Oni, the Mishnah in Shevu'os counts four Chiyuvim (altogether) for a Ba'al ha'Bayis and Oni.)