Rambam - 1 Chapter a Day

Rashi, Bava Metzia 80b, explains that the lender is placed in this category because the lender is considered to be “occupied in the performance of a mitzvah” when he is giving the lender the loan or caring for the security entrusted to him (the responsa of Rabbenu Asher). Since a person occupied in the performance of one mitzvah is not obligated to perform a second mitzvah at that moment, the person giving the loan would not be obligated to give charity to a poor person if asked at this time. The money he thus saves causes him to be considered a paid watchman.

The Ra’avad differs and maintains that if the lender took the security afterwards, he is responsible even if it was destroyed by forces beyond his control. The Rambam’s view is cited by the Shulchan Aruch (Choshen Mishpat 72:2), and the Ramah does not object. The Siftei Cohen 72:9 elaborates in support of the Ra’avad’s position.
The Siftei Cohen also notes that from Hilchot Malveh V’Loveh 3:4, it would appear that the Rambam rules that a lender is liable for security taken after the loan was given when it was destroyed by factors beyond the lender’s control. Nevertheless, it can be explained that that halachah is speaking about security taken without the borrower’s consent, while our halachah is about security given by him willingly.

As stated in Chapter 1, Halachah 2.

If the security is worth the same amount as the loan, the loan is considered to be repaid. If it is worth more, the lender must pay the borrower the remainder. If it is worth less, the borrower must pay the difference. See Hilchot Malveh V’Loveh 13:4 for details concerning this situation.

I.e., at the same time.

Hence, the watchman is not liable even if the object was destroyed by the watchman’s negligence, as stated in Chapter 1, Halachah 3.

To be considered to be working for the watchman, a person must perform services for him at the time he receives the article for safekeeping.

The Maggid Mishneh notes that from a superficial reading of the Rambam’s statements, the difficulty appears that the two are not lending each other the objects at the same time (just like the two must watch the objects for each other at the same time). If, however, two people lent each other articles at the same time, that would be sufficient for the owner to be considered as in the watchman’s employ.
The Maggid Mishneh quotes other opinions that maintain that lending a person an article is not considered sufficient for the borrower to be considered in that person’s employ. For the borrower is not doing anything on behalf of the lender. He maintains that the Rambam could also accept such a premise and could have merely used more general wording in this halachah. He does note that Hilchot She’ilah UFikadon 2:7 appears to support the first interpretation. Nevertheless, even in that source, the other conception could also be acceptable.
The Merkevet HaMishneh notes that, according to the Rambam, as long as the owner is obligated to perform even the slightest activity for the watchman, he is considered to be in his employ. Therefore, the fact that the owner is required to bring the watchman an article to borrow is sufficient to have him considered to be in his employ. See also Ramah (Choshen Mishpat 305:6) and commentaries.

For they each receive a favor in return for taking care of the article belonging to their colleague. In contrast to a watchman who is working for the owner of an article, a paid watchman is responsible when an article is lost or stolen.

Sefer Me’irat Einayim 306:1 states that this ruling applies only to a craftsman who works as a contractor. If, however, the craftsman works for an hourly wage, he is not considered to be a paid watchman. The Siftei Cohen 306:1, however, does not accept this distinction and maintains that the same rule applies in both instances.

The craftsman benefits from having the object placed in his care, because only in this manner will he be able to receive a wage for fixing it. This is sufficient to have him considered to be a paid watchman.

His wording indicates that he no longer desires to keep the object in his possession and is doing so solely as a favor for the owner. Hence, he is considered to be an unpaid watchman.

His words indicate that he will hold the object as security until he is paid for his work. This is also a benefit for him and is sufficient for him to be considered a paid watchman.

Even though the employer gave him only wood, he is liable to make restitution for the entire article. For the article was completed before he broke it.

The article always belongs to its owner. Hence, if its value is increased by the craftsman's work, the owner of the article reaps the profit. Certainly, he must pay the craftsman for his work, but the two - the craftsman's wage and the increase in the value of the article - are two unrelated issues.
Moreover, even if the article did not exist previously, all that existed were the raw materials, since those materials belong to the owner and he hired the craftsman to make the article, the completed article belongs solely to the owner. The craftsman does not have a share in it.
The Shulchan Aruch (Choshen Mishpat 306:2) quotes the Rambam’s view. The Siftei Cohen 306:3, however, cites many Rishonim who rule that a craftsman does acquire a share in the increase in the value of the article. Therefore, he maintains the question should be considered an unresolved point of law. Hence the craftsman is required to pay only the value of the article which he originally received.
See also the Or Sameach, who quotes the Ra’avad, who explains that a craftsman acquires a share in the increase in the value of the article only when he does work at a professional standard. In the instances mentioned in this halachah, the craftsman’s work is not professional. Hence, he does not acquire a share in the article’s increase in value.

For in its present state, the wool is of no value, and it was the dyer’s negligence that caused the loss.

In his Commentary on the Mishnah (Bava Kama 9:4), the Rambam explains that this refers to an instance where everyone would agree that the fabric is dyed the desired color, but the color appears unattractive and no one would desire to purchase such an article.

Rashi, Bava Metzia 117b, interprets this as including the price of the fuel for the fire, the raw materials of the dye and the price for his time as a common laborer, not as a skilled craftsman.

Since the craftsman deviated from the owner’s instructions, he does not receive his full wage.
Instead, he is given slight compensation for his expenses.
In his Commentary on the Mishnah (loc. cit.), the Rambam explains the situation in detail: Originally, the garment was worth a dinar. After it is dyed, it is worth a dinar and a half. It cost the dyer one fourth of a dinar to dye it. The owner is liable to pay the dyer only a fourth of a dinar.

For example, in the above situation, if it cost the dyer three fourths of a dinar to dye the article, he should be paid only half a dinar.
The Rambam’s ruling resembles those applying to a person who sows a colleague’s field without permission (Hilchot Gezeilah V’Avedah 10:4). It would appear that the reason for the comparison is that the craftsman has no permission to perform work below the standards of his craft. Hence, he is considered to be working with a person’s article without his permission.

The Ra’avad differs with the Rambam’ s ruling, maintaining that if the owner is willing to accept the value of the original article, there is no reason why his request should not be heeded. [Significantly, in the first edition of his Commentary on the Mishnah (loc. cit.), the Rambam also states this view. When rewriting that text, he altered his interpretation, however, to match his ruling here.]
From the Rambam’s Commentary on the Mishnah, it appears that the Rambam’s intent is that the owner cannot compel the craftsman to pay for the wool and accept the article. Needless to say, if both parties are willing, such an agreement is acceptable.

Although he is an expert, we do not say that the difficulty is considered to be a factor beyond his control - in which instance, as a paid watchman, he would not be held liable. For with an extra measure of care, the difficulty would not have occurred. Since he is receiving payment, he is required to take that extra measure of care.

Before wheat is ground, the kernels should be soaked in water so that the outer shell will be easily removed when the kernels are crushed. This technique will produce refined flour.

Our translation is based on Rashi’s commentary on Bava Kama 99b.

I.e., he slaughtered it in a manner that violated the laws of ritual slaughter, causing it to be unacceptable as food for a Jew.

The Shulchan Aruch and the Ramah (Choshen Mishpat 306:5) state that when there is a halachic question whether the slaughter is acceptable or not, even when it is customary to rule that the meat is forbidden, we do not require the slaughterer to make restitution. Since there is a doubt involved, we do not expropriate money from its owner.

The same laws apply to a miller, a baker or other professionals (Maggid Mishneh).

Since he is not receiving payment, he is not required to take extra care. And since he is an expert, we consider making an error to be a factor caused by forces beyond his control. Therefore, he is not held liable.

For since he is not an expert, it his likely he will not perform the slaughter - or other professional skill - in an acceptable manner. Hence, taking the initiative to perform that activity is considered to be negligence, for which he is liable.

I.e., the person was not sure if a coin was genuine and therefore consulted a money changer for his opinion. The money changer told him the coin was of value, and later it was discovered that he erred, for the ruling authorities had disqualified this currency.

Bava Kama, loc. cit., does not mention a distinction between whether a money changer charges for his services or not. The Rambam, nevertheless, makes such a distinction, based on the comparison to a ritual slaughterer.
The Rashba and others, however, do not extend the comparison to these details and do not differentiate between a money changer who charges and one who does not. An expert money changer is always released from responsibility. The Rashba’s rationale is that slaughtering requires extra effort and care, and this cannot be required of the slaughterer unless he is paid. Evaluating a coin, by contrast, is a question of knowledge, and either the person knows or does not. The Shulchan Aruch (Choshen Mishpat 306:6) cites the Rambam’s view.

For otherwise the money changer may look at the coin merely superficially, without paying careful attention.

E. g., they were about to conclude the transaction and asked the money changer’s opinion. After hearing his advice, they consummated the deal.

Since the damage that he performed is obvious, he must prove his claim if he wants to absolve himself of responsibility.

This - like a ritual slaughterer or money changer - is considered to be a profession that requires expertise.

I.e., the person plants the trees and cares for them year after year, in return for half of the produce the land yields.

It appears to be the Rambam's intent is that he did not realize a profit; the trees did not bear enough fruit to yield a viable profit margin.

I.e., the lack of income that was caused by his unsuccessful planting.

A stipulation made facetiously, which the planter never intended to keep. As explained in Hilchot Mechirah 11:6, such a stipulation is not binding.

Who does not plant the trees, but merely takes care of an existing orchard.

The Ramah (Choshen Mishpat 330:3) states that the planter may not terminate the relationship without the consent of the owner of the land. The Siftei Cohen 330:1, however, questions the Ramah’s ruling, maintaining that if the planter agrees to the division of profits stated by the Rambam, he should be allowed to quit whenever he desires.

The Ra’avad and the Tur maintain that this law applies not only to professionals employed by the community in these capacities, but also to those employed by individuals. From the conclusion of the Rambam’s statements, “for they were appointed by the community,” it would appear that there is a difference of opinion concerning the matter. Shulchan Aruch (Choshen Mishpat 306:8) quotes the Rambam’s decision, while the Ramah mentions the view of the Ra’avad and the Tur.

The Magid Mishneh explains that even when the slaughterer is paid for his services and thus must reimburse the people for the loss, he still should be removed from his position, because although the people did not suffer financial loss, they did not have meat when they needed it. That is a communal problem sufficient to warrant his removal.

I.e., he wrote it in a manner that did not conform to law.

The Ramah (loc. cit.) quotes the opinion of the Mordechai, who maintains that this decision applies even if the teacher failed to instruct them for only one day. The time during which he did not teach them or taught them incorrectly is a loss that can never be corrected.

The Maggid Mishneh states that if the teacher himself knows the correct interpretation and the students alone were the ones that erred, the teacher need not be removed.
See Hilchot Talmud Torah 2:3, which speaks about the care a teacher must take in teaching his students correctly. See also the severe consequences suffered by Joab’s teacher for causing him to come to a misunderstanding of a verse in the Torah.

The Maggid Mishneh [and the Ramah (loc. cit.)] quote the Rashba, who states that although a warning is not necessary, it must be an established fact that the individuals in fact err in the execution of their responsibilities, or they must be warned.

Since they are involved in a profession where the risk of an error that cannot be corrected is a constant factor, they have a constant warning to perform their work professionally (Bava Metzia 109a).