Rambam - 1 Chapter a Day

I.e., he must take possession of it by executing a formal kinyan.

The Maggid Mishneh points to Bava Metzia 10a, which questions why the finder does not acquire the object by virtue of its being found within the square of four cubits by four cubits around him. He explains that the Talmud gives two answers:
a) that we are speaking of an object discovered in the public domain. The provision of our Sages that a person can acquire an article by virtue of its being found within four cubits of his person does not apply in the public domain.
b) that since the person fell on the article, he indicated that he did not desire to acquire it by virtue of its being found within four cubits of his person.
The Maggid Mishneh states that the Rambam follows the second interpretation. For if he followed the first interpretation, it would have been necessary to be more explicit and say that this law applies only in the public domain.
In the Kessef Mishneh and the Beit Yosef (Choshen Mishpat 268), Rav Yosef Karo differs and explains that the Rambam follows the first interpretation (as do Rabbenu Yitzchak Alfasi and Rabbenu Asher). On this basis, the Ramah (Choshen Mishpat 268:1) rules that a person who falls on an article in an alleyway (which is not considered part of the public domain) acquires it because it is found within four cubits of his person. See, however, Shulchan Aruch (Choshen Mishpat 198:12).

For the rider’s colleague acts as his agent and acquires it for him.

For he did not accept the agency given him by the rider. If the rider had told his colleague, “Acquire the article on my behalf,” the colleague would have had to protest the appointment for his claim not to be accepted [Bava Metzia 9b, 10a; Maggid Mishneh; Ramah (Choshen Mishpat 269:6)].

For had he really intended to take it for himself originally, he would never have given it to the rider.

E. g., Reuven picked up a lost object on behalf of Shimon without receiving any instructions from him. Since Reuven’s action is to Shimon’s advantage, we assume that Shimon would consent. Thus, de facto, Reuven is accepted as his שליח [“agent” (Bava Metzia 9b)]. Even if later Reuven desires to recant and take the object for himself, he cannot. For Shimon has already become its legal owner (Sefer Me’irat Einayim 269:1).

This refers to an instance where each person acknowledges the assistance of the other. By lifting the article up together, each is thus taking possession of the article for himself and for his colleague. Thus, they become partners, each with a share of half the article.

The acquisition of an article on behalf of another person is a function of שליחות “agency.” Since these three types of individuals do not have a developed mental capacity, they are unable to serve as agents.

As mentioned in the notes on the previous halachah, when two people lift up an article, each is acquiring the article on behalf of himself and the other person. In this instance, the deaf mute cannot acquire the article on behalf of the mentally competent individual, so the mentally competent individual does not acquire his share.
One might think, however, that the deaf mute would acquire half of the article, for, as stated in Halachah 12, according to Rabbinic law he can acquire an article for himself, and a mentally competent individual can surely acquire an article on his behalf. Nevertheless, Bava Metzia 8a rules that since the mentally competent individual did not acquire his half of the article, he does not act as an agent for the deaf mute regarding the other half.
Thus, if a third person pulls the article away from both of them, he becomes its legal owner. He must, however, reimburse both the mentally competent individual and the deaf mute for the portion that they held in their hands. For they do acquire at least that portion of the article [Shulchan Aruch (Choshen Mishpat 269:4)].

See Halachah 12, which explains that one deaf mute can acquire an article he picks up for that reason. The same principle applies when two pick up an article together.

Leading means to direct an animal, as the driver of a carriage does to his horses. It is also a form of meshichah.

In Hilchot Mechirah 2:6, the Rambam defines meshichah as causing the animal to move both a foreleg and a rear 1eg in the direction one desires.

I.e., both leading and drawing an animal after one are considered effective means of acquiring the animal. Hence, both individuals share in the ownership of the article, as stated in Halachah 3.

I.e., when are 1eading the animal and drawing it after oneself equal?

I.e., if one or two people lead a camel, they acquire it, but when one leads and one draws it after himself, the 1atter alone makes acquisition, for a donkey is normally led, while a camel is drawn after one.
This represents the opinion of the Rambam. The Tur (Choshen Mishpat 197) quotes the opinion of his father, Rabbenu Asher, that one of the two - leading a camel or drawing a donkey after one - is not an effective means of acquisition. The Sages did not know which one was not effective. Therefore, each alone is considered an effective means of acquiring an ownerless article. When, however, a person must press his claim to ownership against a person who has used an effective means of acquisition, the matter is one of doubt. This is also the opinion of the Ra’avad. In the Kessef Mishneh and the Shulchan Aruch (Choshen Mishpat 271:1), Rav Yosef Karo follows the Rambam’s view.

With regard to a sale, this wou1d be an effective means of transfer, for it would constitute the kinyan of mesirah. When, however, there is not another person involved, this process is not effective.

Holding the animal’s reins is not sufficient. To acquire the animal, the person must cause it to move in the direction he desires.

For everything in his estate is ownerless, as stated in Hilchot Zechiyah UMatanah 1:6, 2:1.

Sefer Me’irat Einayim 271:4 maintains that the person acquires the entire reins (in contrast to the situation mentioned in the following halachah), because he can draw them into his possession. The Siftei Cohen 271:2 maintains that as long as he does not actually draw the reins into his possession, he acquires only the portion that he is holding, as in the following halachah.

There is a difference of opinion among the Rabbis if a person who rides on an animal must force it to move with his feet in order to acquire it. It would appear that the Rambam considers riding alone to be sufficient. Rabbenu Asher maintains that the rider must also cause the animal to move. See the Kessef Mishneh and also the Rambam’s wording in Hilchot Mechirah 2:6.

A person’s courtyard is considered an extension of his person. Therefore, just as he acquires an article placed in his hand, he acquires an article placed in his courtyard.

E. g., it is surrounded by a fence or the like. In such an instance, an article that is placed there will not ordinarily be taken by anyone other than the owner of the property. Therefore, he acquires it without having to make a statement of intent.
The Ramah (Choshen Mishpat 268:3) quotes the Mordechai, who states that this applies only when a person knows of the lost object or has reason to suppose that it might be located in his property. If, however, he is totally unaware of its presence, like the buried treasure mentioned in Chapter 16, Halachot 7-8, he does not acquire it.

Since they are accessible to the public, articles placed there may be taken by anyone other than the owner of the property.

As the Rambam continues to explain, for an article to be acquired by virtue of its being placed in such a property, the two conditions he mentions must be met. The Rashba and Rabbenu Asher differ and maintain that as long as the person is standing within his field, he need not declare his intent to acquire the article.
The Shulchan Aruch (Choshen Mishpat 268:3) follows the Rambam’s opinion, while the Tur and the Ramah follow that of the Rashba and Rabbenu Asher.

The Maggid Mishneh states that the intent is, within his field, at its side. If he is outside the property, he does not acquire the lost object.

See Halachah 11, from which it is obvious that the laws stated in this halachah apply only to immobile objects.

This measure was chosen because it represents the breadth of an ordinary person standing with outstretched arms.

See Sefer Me’irat Einayim 268:3, which cites an opinion that maintains that a person can acquire an object by virtue of its entering the four cubits adjacent to him only when he is standing still. If he is walking, this is not an effective means of acquisition.

As the Rambam explains in the following halachah, our Sages ordained that the area in a person’s immediate reach be considered equivalent to his private, guarded courtyard. In such an instance, he is not required to make a statement of intent regarding the acquisition of an article.

If two people both saw an article and each claimed it as his own, it is likely that an argument, and perhaps even a physical struggle, would break out. To avoid this, our Sages ordained that the article be given to the person in whose four cubits it is found.

If two people are standing close to each other in such a place, and a lost object comes to rest in a place that is within four cubits of both of them, they both share equally in its ownership [Tur; Ramah, Choshen Mishpat 268:2)].

Since the public domain is crowded, no one person will have a radius of four cubits that will be able to remain his own private area. As such, strife will not be prevented by considering this area to be one person’s private domain.

Since this property has an owner, it cannot be automatically considered to belong to another individual. The Ramban states that this law applies even when the field is not an enclosed and protected property.

Numbers 21:26 uses the word miyado, literally “from his hand,” as meaning “from his possession.” A similar usage is frequent within the Torah and within Talmudic sources. On this basis, the Rambam (Hilchot Gerushin 5:1, based on Gittin 76b) explains:
The Torah’s expression [Deuteronomy, 24:1], “He shall... place it in her hand,” need not be interpreted only [according to its strict literal meaning], that the bill of divorce must be placed in her hand. Regardless of whether the bill of divorce is placed in her hand, her bosom, her courtyard, or given to her agent whom she charged that his hand would be as her hand, the same law applies.

Kiddushin 41 a derives this law from the fact that Deuteronomy 24:1, the verse that teaches us that an agent may act on a person’s behalf, speaks about a person past the age of majority. (See also Hilchot Sh’luchim VeShutafim 2:2.)

At which point his acquisition is valid according to Rabbinic law alone, as stated in Halachah 12.

I.e., even if the other pursuers actually capture the deer or the doves, since the owner of the field could have captured them, and they were in his field, he is granted possession.
Sefer Me’irat Einayim 268:15 states that in this instance, as in the instance described in Halachah 8, the Tur does not require the owner to state “May my field acquire them for me.” In this instance, however, the Ramah (Choshen Mishpat 268:4) accepts the Rambam’s view.

For he has no way of actually taking possession of these animals.

I.e., if one of the other people chasing the animal(s) catches it, he acquires it although he and the animal are located in a field that belongs to another person.

Even if he could not catch the deer or the doves, since the ownership of them is transferred by another person, he can acquire them.

He does not have to state: “May my field acquire them for me.”

If these individuals were denied the right to possession, this would probably cause strife between their relatives and the person who took the article from them.

Since these three individuals are not mentally competent, they are not capable of acquiring an ownerless object according to Scriptural law. Nevertheless, our Sages gave them this prerogative for the above reason.

The person who took the article is its legal owner according to Scriptural law. Therefore, even according to Rabbinic law it is not expropriated from him.

See Chapter 6, Halachah 16.

Since these children derive their livelihood from their father’s household, our Sages granted him the right to any lost object they find, lest strife arise if they withheld it and took it as their own (Bava Metzia 12b).

The term na’arah refers to the six month period following the time when a girl of twelve or more exhibits signs of physical maturity (Hilchot Ishut 2:1-2).

A father is entitled to all the financial benefit that accrues because of his daughter who is below the age of majority. This law applies independent of whether or not he supports her. There are even situations where he is entitled to sell her as a maidservant. Even when he is forced to take this step, he does not forfeit his privilege to her earnings.

For they are considered an extension of his person, having no independent financial capacity of their own.

As stated in Hilchot Ishut 12:3, one of the privileges a woman grants a husband as pan of the marriage contract is the right to any ownerless articles that she discovers. This is a Rabbinic decree, enacted for the same rationale described above: Since he supports her, he is likely to become upset if she is allowed to maintain possession of a lost article that she discovers.

Since he is not supported by his father, he is granted an independent financial capacity according to Rabbinic law (Bava Metzia 12a).

For they retain their own financial capacity during servitude (ibid.).

In such a situation, the woman’s husband is still obligated to support her. Nevertheless, our Sages did not require her to give him a lost object that she discovers. The rationale is that there is strife between them anyway, and the woman is therefore allowed to keep what is rightfully hers.