Rejection: It should not bring a Beraisa, since it can bring a Mishnah.

Implied question: It says above (4a) "straw, and he is not destined to clear it away, or earth Stam, R. Yosi and Rabanan argue about these." In the Mishnah in Ohalos, Rabanan do not discuss straw at all!

Answer: In any case, we learn from a Kal v'Chomer from earth that [Rabanan hold that straw] requires Bitul.

Implied question: Why is it obvious that if he was Mevatel straw, Rabanan hold that it diminishes?

Answer: We properly learn this from a Kal v'Chomer from grain, for which Bitul helps.

Implied question: Why does it say there that R. Yosi and Rabanan argue about Stam earth?

It could have said that they argue about earth that he will not clear away, for Rabanan argue also about this, and say that it is not Batel, unless he was Mevatel it. "He is not destined to clear it away" does not mean that he was Mevatel it, like is proven there!

Answer: Due to R. Yosi, it mentioned Stam earth. [The Tana] was not concerned to elaborate and mention both [cases of earth about which they argue].

Implied question: [Rav Huna, who said this,] did not know the Beraisa that [the Gemara] brings (for it refutes him. If so, what was his source that the Mishnah is R. Yosi?)

Answer: He knew that R. Yosi discussed that Mishnah in Ohalos (but he did not recall exactly what he said about it - Tosfos ha'Rosh).

Support: We find like this in Yoma (14b) regarding "who taught [Maseches] Tamid? It is R. Shimon Ish ha'Mitzpah."

Explanation: The Tum'ah breaks through and ascends, like it teaches in Ohalos (7:1).

Question: R. Yosi holds that contained Tum'ah does not break through, in Chulin (125b)!

Citation (125b - Mishnah - R. Yosi): If (interwoven) bed ropes or poles in a window were stretched in the air over a Mes, one who touches (puts his hand) over a rope is Tahor. We establish it when the ropes are close [to the Mes, i.e.] less than a Tefach [above it].

Answer (Ri): Still, Bitul helps so that Tum'ah will not come to Kelim next to [the Mes, for there is not the Shi'ur of an Ohel].

Implied question: R. Yosi said in Sukah (21a, that the one who takes water for Mei Chatas) stands in his place and fills, due to [concern for] Kever ha'Tehom (an unknown grave underground. He holds that contained Tum'ah does not break through!)

Answer: Only regarding a grave, it says "Oh b`Kever", [to teach that] one who towers over a grave is Tamei, but normally R. Yosi holds that [contained Tum'ah] does not break through, and [above] is Tahor.

Question: If so, why did Rav Huna say that he does not put [straw] in his box and feed, since even Leha'amid (to bring the animal to there) is forbidden, even though he does not move [the straw]?

Answer: Had he said "one may not be Ma'amid", we would not know the reason, as long as he did not teach us that one may not move [the straw];

Therefore, he taught that one may not put in his box, lest [the height of the straw] be diminished (less than 10) without his awareness, and automatically we know that to be Ma'amid is forbidden.

Explanation #1 (Rashi): "Gov" is a pit.

Objection: A pit does not apply to straw!

Explanation #2: Some say that the word "Gov" is like "Kash u'Gvava" (gathered straw).

Explanation: This is said in astonishment. I.e. temporary Mechitzos, like above (72b), we rule like R. Yehudah ha'Savar, who says that according to Beis Hillel, they make one Eruv for everyone in a case of Mechitzos that do not reach the ceiling;

Also there he discusses temporary Mechitzos, like I explained there (72a DH bi'Mechitzos).

Implied question: Normally, Abaye holds that Lavud helps in such a case, like we find above (16b) regarding ropes (through Lavud, they are considered a Mechitzah)!

Answer: Here he does not consider it [Lavud], for also [full] Mechitzos that do not reach [to the ceiling] are not considered [Mechitzos] here.

Observation: There are residents who come on Shabbos who are forbidden, e.g. a Yisrael and a convert dwelling in one Dirah, and the convert died before Shabbos, like it says above (70b);

Here we discuss residents who come on Shabbos through the falling of a Mechitzah between two Chatzeros. Rav and Shmuel argue about this, and R. Oshaya asked about this below (93b).

Explanation #1 (Rashi): Regarding the Heter of others, one (Bitul or locking) suffices. However, for him (the Mevatel), he must distance himself, lest he come to move;

Similarly, this Tana holds that anyone who is Mevatel Reshus must lock [his door].

Question: If one person of the Chatzer forgot and was not Me'arev, how can he enter and exit, if he cannot go through the Chatzer, if he must lock the door [of his house]?!

Answer: Perhaps he must lock the door, and when he needs to enter or exit, he opens and locks it afterwards.

Explanation #2: Only here he must lock the door, for until now they were used to carrying without any Eruv, for the straw interrupted, and there is concern like [the Gemara] says. Since he is accustomed, he will come to carry;

However, if one of the people of the Chatzer forgot and was not Me'arev, in that Chatzer they were used to carrying only through an Eruv or Bitul Reshus. Therefore, he need not lock the door.

Assertion: Even here, he needs to lock the door only the first Shabbos after the reduction [of the straw], since the previous Shabbos they moved without an Eruv and without Bitul Reshus;

However, the next Shabbos he need not lock, for it is unreasonable that forever he must lock, and we would not equate him to other cases of Bitul, because once a Mechitzah interrupted there.

Implied question: Above (68a), Rava told them "clear out my Kelim from the men's house to the women's house", and Rashi explained that he cleared out his Kelim, lest he take them out from there to the Chatzer. This connotes a little that we are concerned lest he carry (even though he normally needed an Eruv)!

Answer: Just the contrary, it connotes that they did not need to lock the door. Also Rava commanded to clear out his Kelim, it connotes that only because he was Mevatel he needed to clear them out, lest he take out b'Shogeg (which is like retraction of his Bitul), and forbid [them];

However, if he was not Mevatel, there would be no need, not for him and not for other members of the Chatzer, to clear out Kelim or lock.

Defense (of Rashi): We can say like Rashi explained that there is concern lest he come to carry only when he sees others carrying.

Conclusion: It seems more that the reason is lest he take out and be Machazik (retract his Bitul, like Explanation #2).

Limitation: It seems that if the Halachah follows R. Yehudah, who says that [if he took out] b'Shogeg he does not forbid, it seems that the reason is not lest he take out b'Mezid and forbid, for we need not be concerned for lest he be Motzi b'Mezid, which is forbidden.

Implied question: This Beraisa is difficult for Rav, who said above (68b) that they can return and be Mevatel!

Answer: He establishes that Tana'im argue about this, like Rav Sheshes said there.

Pesak (R. Tam): According to R. Yochanan, who said in Bava Metzi'a (12b) regarding a Metzi'ah that "Gadol" is not literally an adult. (Rather, it is one whose father does not feed him), and the same applies here, one must be careful not to be Mezakeh the Eruv through his adult son whom he feeds, for [the son's] Yad (power of acquisition) is like his father's (he acquires only for the father, so he cannot be Mezakeh for others).

Implied question: Shmuel argues with [R. Yochanan] there, and says that "Gadol" is literally an adult!

Answer: We hold like R. Yochanan against Shmuel.

Question: According to R. Yochanan, how is a minor [whose father does not feed him] Zocheh?

Answer - implied question: No matter what you will say, also an Amah Ivriyah is a minor, for if she brought two hairs [of puberty after 12 years], what is she doing by [her master?! Once she becomes a Na'arah, she is free], and it teaches that he can be Mezakeh through her, even though normally a minor cannot be Zocheh for others!

Answer: Shitufei Mavo'os, which are mid'Rabanan, are different. It says so explicitly in Gitin (64b).

Question: How can an Amah Ivriyah be Zocheh? Her master feeds her!

Answer #1 (R. Tam): She eats due to her work. (It is as if she feeds herself.)

Answer #2 (Ri): The reason that one who is fed (his Yad is like the Yad of the one who feeds him) helps only for a son, for it is normal to feed him, and if his father will not get his Metzi'ah, there is concern lest [the father be upset and] he not feed him;

However, others whom a Ba'al ha'Bayis feeds, their Metzi'os do not belong to him.

Distinction: However, his daughter, even a Na'arah (who is an adult) and he does not feed her, her Metzi'ah is his due to enmity, lest he marry her off to a disgusting man or leper (he would pay the father much for this, for no one wants to marry him).

Source: It says so in Kesuvos (47a) that the reason of enmity applies even when he does not feed her, and even to a Na'arah.

Citation: In Nedarim (88b), we establish this when she has a house in the Mavuy. Since she acquires for herself, she acquires also for others;

However, if she does not have a house [in the Mavuy], no (she cannot acquire for others), for a woman's Yad is like her husband's Yad (she acquires only for him).

Question: If she receives Pras (he feeds her), she need not acquire for herself (she need not be part of the Eruv), like it says above (73a) that R. Yehudah ben Beseira permits women and forbids slaves!

Suggestion: That is only when the Eruv comes to [the husband or master. Here, it does not come to him.]

Rejection: Since he is Mezakeh for [the others], presumably he places the Eruv in his house.

Summation of question: And if she does not receive Pras, even if she does not have a house [in the Mavuy] she can acquire for them, for her Yad is not like her husband's Yad!

Answer #1: Here, her husband gives to her money for food. In such a case it is not considered that she receives Pras, unless he brings the food and drink from his house and she eats.

Answer #2: Here, her earnings suffice [to feed herself]. Regarding Metzi'ah and everything, her Yad is like her husband's Yad, for it is as if he feeds her, but regarding receiving Pras, it is as if she does not.

Question: If so, his Katan son or daughter can be Zocheh their Eruv for others in such a case through a Migo (since they acquire for themselves...) when they have a house in that Chatzer...

And similarly his male or female Kena'ani slaves, for they have Zechiyah (acquisition) regarding Eruv, since they forbid when they have a Chatzer or house, like it says above (73a, that R. Yehudah ben Beseira) forbids slaves and permits women!

And regarding Eruvei Techumim, we say below (82b) that a master is Me'arev for them. Will we say that if their master is not there, they cannot be Me'arev?! Presumably, Rabanan enacted for them Zechiyah regarding Eruv. (If so, why does the Mishnah say that one cannot be Mezakeh through them?)

Answer (Ri): According to the conclusion in Nedarim, [our Mishnah] is like R. Yehudah ben Bava, who forbids women and permits slaves above (73a), and both of them receive Pras. His wife needs to be Me'arev, but a slave need not be Me'arev.

Note: Tosfos did not answer his question regarding Ketanim. Keren Orah says that they are like slaves. Tosfos ha'Rosh says that normally, they do not have their own house.

Implied suggestion: From here we can prove that a Tefach suffices for Hagbahah!

Rejection: Shitufei Mavo'os, which are mid'Rabanan, are different.

Support: [The Tana] does not come here to teach the law of Hagbahah everywhere!

Explanation (R. Tam): This Malei Lugmav is not truly Malei Lugmav (the amount that one can hold in his mouth when his cheeks stick out). Rather, it is like it explains in Yoma (80a), the amount that if he puts it on one side of his mouth, it looks like Malei Lugmav (one cheek sticks out).

Support: In Yoma (80a), it is proven that Malei Lugmav is more than a Revi'is, and in Pesachim (108b) it says that a Revi'is is the Shi'ur of the four cups, and the cup of Kidush is one of them;

How could one taste [a true] Malei Lugmav? There is not so much in the cup! (It is only a Revi'is. One could question this proof. Perhaps the drinking of the Mekadesh and those who were Yotzei through him join to Malei Lugmav, like the Ritva brings from Tosfos! Or, a Revi'is is the Shi'ur for the four cups, but the one who says Kidush, his cup must hold Malei Lugmav. Or, if he is small, his Malei Lugmav is a Revi'is or less. Perhaps Tosfos understands that in every case a Revi'is suffices, even for a normal size person who is alone.)