We continue in Chapter 9 of Tractate Bava Kamma, to Mishnah 2. The Mishnah continues to discuss the obligation to return a robbed object, and here it deals with cases where the value of the object decreased while in the robber's possession.
"Gazal behemah vehizkinah, avadim vehizkinu - meshalem kish'as hagezeilah" - if one robbed an animal and it grew old, or slaves and they grew old, he pays according to the time of the robbery:
A robber who robbed an animal and it aged until it is no longer capable of the production and work it was accustomed to, and similarly one who robbed slaves and they aged until they cannot reproduce or work as before - he cannot return the animal or the slave as they are, for this is no longer the same slave and no longer the same animal, and their productive capacity is gone. Therefore, he pays according to the value the item had at the time of the robbery.
"Rabbi Meir omer ba'avadim: omer lo harei shelcha lefaneycha" - Rabbi Meir says regarding slaves: he says to him, here is yours before you:
According to Rabbi Meir, the law is different for slaves. Slaves are compared in many places in the Torah to land, to real estate, and the rule is that land cannot be robbed: one can invade it, but one cannot take it from its place. By virtue of this comparison, slaves are also not literally robbed; rather, one can only take possession of them, like someone who invaded his friend's land.
And just as land can be returned in any condition by saying "here is yours before you" - even if it was flooded by river waters or has meanwhile become a toxic waste dump, the squatter vacates it and says to the owners: here is your land before you, take it - so too with a slave: the fact that he aged does not matter, and he returns him as he is.
Practical Halachah:
The Bartenura rules like Rabbi Meir, and this is seemingly astounding: in a dispute between Rabbi Meir and the Sages, the halachah follows the Sages. However, the Gemara says that "Rav switches" the opinions - meaning the Sages, who are the majority, are the ones who hold that slaves are linked to land to the extent that one can say to the owners: here are your slaves before you, go and take them. Therefore, the halachah follows the opinion brought here in the name of Rabbi Meir.
"Gazal matbeia venisdak, peiros vehirkivu, yayin vehechmitz - meshalem kish'as hagezeilah" - if he robbed a coin and it cracked, fruit and it rotted, wine and it soured - he pays according to the time of the robbery:
"Matbeia venisdak" - a coin and it cracked - the coin broke or split in two, and it can no longer be used as a coin.
"Peiros vehirkivu" - fruit and it rotted - most of it rotted and is no longer fit to be eaten as before.
"Yayin vehechmitz" - wine and it soured - the wine spoiled and became a type of vinegar.
In all of these, a physical change occurred in the object, and the change acquired it for the robber. It is not in his power to return the item he took, and therefore he pays the value it had at the time of the robbery.
It is worth mentioning that these laws apply equally to a thief and a robber, except that most cases of taking property are theft: it is rare for a person to take by force and openly, and mostly the taking is done in secret, when no eye sees. In the case of theft, besides paying the value of the object, the thief is also obligated to pay double.
Invisible damage:
In contrast to the previous cases, there are instances where the change is not a physical change in the object itself, but rather a legal and conceptual change - a purely halachic change. Such a change is called 'invisible damage', and it is not considered a change that acquires the object for the robber:
"Matbe'a venifsal" - the government declared that the coin is no longer legal tender, and is no longer accepted in this location. The coin itself has not changed and can be used elsewhere, and therefore he says to him: Here is your coin before you, go and use it elsewhere. This is the simple case that everyone agrees upon. However, the poskim disagree, and this dispute continues all the way to the Shulchan Aruch, regarding a coin that is no longer accepted anywhere in the world, whether this is considered a change that requires assessing a new value.
"Terumah venitmei'ah" - the Terumah became tamei in the thief's possession, and the kohen can no longer eat it or drink the Terumah wine. Nevertheless, this is merely a halachic change; the wine is the same wine it was, and he returns it as is.
"Chametz ve'avar alav hapesach" - the stolen chametz remained in the thief's possession during Pesach, and the Sages decreed that chametz that was not destroyed in a Jew's possession on Pesach becomes rabbinically forbidden for consumption and benefit. The stolen cookies are no longer fit for consumption, but they are the exact same cookies, and there is no physical change in the object.
"Behemah vene'evdah bah aveirah" - an animal that was designated to serve as a korban, and while in the thief's possession, a sin was committed with it: it was worshipped or bowed down to, or used for bestiality. Even if there is only one witness to this, it is forbidden as a korban, yet it still looks like the exact same animal.
"O shenifselah me'al gabei hamizbe'ach" - an animal that was consecrated as a korban and developed a blemish that invalidates it from being offered, such as a cataract in the eye - a defect that is not obvious to an observer.
"O shehayetah yotzah lisakel" - an animal that killed a person, and its verdict was finalized in beis din for execution, for from that moment it is forbidden for benefit.
In all of these cases, since the change is not physically noticeable to an outside observer, "omer lo: harei shelcha lefaneycha" - the thief returns the object to its owner and says: Here is your cow before you, take it, even though in practice the victim has no use for it.
In summary - double payment for theft: We will reiterate and emphasize that these laws apply to robbery as they do to theft, except that the thief, who takes in secret - which is the most common way of taking money - is also liable for double payment. Even when he says "Here is yours before you" and returns the cow that has become forbidden for benefit, it is incumbent upon him to separately pay the double payment: if the cow was worth one hundred, he must pay an additional one hundred as double payment.