Answer: This is only regarding one who sells or rents to his friend, when there is one who is Moser to him, that he acquires. However, regarding property of a convert, who will be Moser to him, that he will acquire?!

Objection (Ri): It says explicitly in Bava Kama (52a) that one does not acquire through handing over the key! Handing over the key helps only so that he need not say to him "go make Chazakah";

Only Bedikah depends on handing over the key, for whoever has the key must check, for he is able to enter and check.

Objection: [The Rashbam] explained that locking the door does not acquire. Gitin 77b connotes unlike this;

It says there "she should close the door and open it" (to acquire the room, and also the Get inside). This shows that through mere locking she acquires. She could not affix a lock, for it was Shabbos!

Implied question: One may not acquire on Shabbos!

Answer: Regarding a Shechiv Mera it is permitted, lest he be frantic [if he cannot carry out his intent, and this could precipitate his death], like it says below (156b).

Implied question: Locking the door is no better than Mavri'ach Ari (which does not acquire)!

Answer: We say below only that putting a rock to dam up water (to prevent flooding) is Mavri'ach Ari;

However, here that he locks against everyone, and does not allow anyone else to enter, it is proven that the house is his, and he acquires through locking alone.

Support: This is proven below (57a) regarding the Mishnah of matters that have a Chazakah, and matters that have no Chazakah;

The Gemara asks what is the difference between the Reisha and Seifa, and Ula answers that anything that does not acquire in property of a convert [is not a Chazakah to prove ownership];

The Seifa teaches "if he entered chickens into the house, this is a Chazakah, and it acquires also in property of a convert;

There, the reason is because presumably, when he entered chickens, he locked the door to guard them. This shows that one acquires through locking the door!

Question (Rashba): It says below (53b) that if Reuven built mansions on property of a convert, and Shimon set up doors, [Shimon] acquired;

There we discuss when he locked [the doors], for if he did not lock, why did he acquire? He merely arranged bricks, like Reuven, for anyone can enter if he did not lock it!

Answer: Surely, we discuss when he locked, and it connotes that [he acquired] only because he set up doors, but if he did not set up doors, he does not acquire through locking!

Explanation (Rashbam): The text does not say "in front of him", because in property of a convert, "in front of him" does not apply.

Rebuttal: This is not difficult. We can say that the text says "in front of him" due to one who gives a gift and brothers who divided!

Support #1 (for Rashbam): However, [in any case] the text does not say so, for the Gemara deduces from the Beraisa of Rav Sharbiya "in front of him, yes, but not in front of him, no." It should have deduced so from our Mishnah [if the text says "in front of him"]!

Support #2: Rav asked "what is the law regarding a gift?" He should resolve this from our Mishnah, that regarding a gift it teaches "in front of him", if this is in the text.

Explanation: It connotes to [the Makshan] that [the Mishnah says] "what is the case? A Machazik requires three years of Chazakah", i.e. in something to which Chazakah applies;

Therefore, we ask "does Chazakah of three years not apply to these, e.g. one who gives a gift or brothers who divided?!"

Implied question: Shmuel holds in Bava Metzi'a (15a) that a gift gets more rights than a sale, regarding that creditors may not collect Shevach (improvements to the property, from a gift recipient, but they collect Shevach from a buyer)!

Answer: This is after the gift was acquired, like the Rashbam explained (DH v'Rav).

Assertion: The text does not say so. How could we say "also now, he cannot enter"? It says "in order that he can enter and leave"!

Conclusion: The text is like Seforim that say "initially, people could not enter, and now, they can enter. [If so,] he did a great matter!"

Explanation: If so, this is not "Kol she'Hu"! Rather, [initially people could enter with difficulty, and now they can enter easily].

Also the case of locking we must resolve like this.

Implied question: It says in Kidushin (27a) regarding 10 fields in 10 provinces, if one made Chazakah in one of them, he acquired all of them!

Answer: There, he gives to him the money for all of them. Here, we discuss property of a convert, or a gift;

Even though money is not lacking, in any case it is not like a sale in which he gave the money for all of them.

Implied question: He dug a little when he built the foundation! (Digging even a little is a Chazakah.)

Answer: [Digging] helps only in land destined to be plowed.

Implied question: Why is this unlike one who found built mansions, and plastered one [coat] of plaster? He acquired!

Answer: There, he improved property of a convert, i.e. mansions. Here, the property of a convert is land. He did not improve it, for it is not proper to live there as long as there are no doors.

Question: It has a roof. It is proper to enter it when it is sunny to be shaded from the sun, and in the rain due to the rain!

Answer: In any case, it is not proper for fixed residence as long as there are no doors;

Just the contrary, he ruined it (the land)! Initially it was proper for seeding, and now it is not proper for seeding!

Explanation: This is only if he spread them, but if he walked in a house or lied down, he did not acquire;

Even if he found set beds and lied on them, it connotes that he did not acquire, for we need an esteemed Chazakah.

Assertion: In Shabbos (41a), it says "if he bathed and did not anoint initially [with oil, is like water on top of a barrel." The bathing does not help, just like the water does not enter the barrel.] The text [there] should not say "initially", for here it connotes that anointing is after bathing.

Suggestion: Perhaps they used to anoint twice (before and after)!

Rejection: If so, why does it omit here the anointing before bathing?!

Suggestion: We can learn from [Na'ami's directions to Rus] "bathe and anoint"!

Rejection: We can say that that anointing refers to fragrances. Surely that anointing, which was in order to absorb scent, is good after bathing, lest the water remove the fragrances.