1) A THIEF WHO STEALS WOOL AND DYE
QUESTION: The Gemara asks whether there is "Shevach Samanin Al ha'Tzemer" or not: Is the dye on the wool considered still in its original form, or is it considered consumed by the wool? The Gemara explains that the practical difference exists in a case of a thief who steals wool and dye from someone, and then he colors the wool with the dye.
If the dye is considered still in its original form, the thief fulfills his obligation to return the stolen wool and dye by simply returning the dyed wool in its present state. If the dye is not considered present in its original form, the thief must return the wool plus the value of the dye which is no longer present.
The Gemara asks, why must the thief return the value of the dye? Since the wool is now dyed it is worth more than it was worth when he stole it, and therefore when he returns the dyed wool he returns both the wool and the value of the dye!
The Gemara answers that the case is one in which the market price of dyed wool depreciated, and dyed wool is not worth as much as wool that is not dyed since people use dye only on finished garments and not on wool. If the thief must return the value of the dye, he must add some money to the dyed wool that he returns.
RASHI explains that had the only use of dye been for dying wool, the thief would not have been required to add the value of the dye to the dyed wool that he returns. However, since there the option exists to use dye for dyeing garments, a use which would not cause the dye to depreciate in value, the thief must return to the owner the full value of the dye that he stole because of this loss that he causes to the owner. This is also the way the ROSH and NIMUKEI YOSEF explain the Gemara.
REBBI AKIVA EIGER (in Gilyon ha'Shas) asks why Rashi needs to explain that the dye would not lose value when used to dye a garment. The Gemara is understandable just as well even if the dye depreciated in value (after the thief dyed the wool) and any other use that it has will not add up to the dye's original worth. Although the dye has depreciated in value, if the dye is considered consumed by the wool, the thief must return the amount of money the dye was worth at the time he applied it to the wool, and not its present value. This is the manner of assessing every stolen item which one must repay! If the dye is considered present, the thief may return the colored wool in its present form.
ANSWER: Rebbi Akiva Eiger seems to understand the words "Zol Tziv'a" ("the dyed wool depreciated") to mean that after the wool was dyed, dye fell in value so that it was no longer worth as much as it was worth at the time that the thief applied it to the wool. Indeed, this is the way the RAMBAN (in Milchamos) explains these words of the Gemara.
However, as RABEINU MOSHE KAZIS explains, Rashi seems to understand these words differently. Rashi implies that the price of dye did not change from the time that the thief stole it until the time that he returned it. Rather, dyed wool was always low in value, in contrast to dye alone, or dyed garments, which are worth more than dyed wool. This is why Rashi adds the words that dyed wool "depreciated in value in the world," meaning that the low price was due to the nature of the world and not due to fluctuations in the market.
Since, according to Rashi, the Gemara does not discuss a case in which there was a depreciation in the value of the dye, even if the dye is not considered present the thief does not have to pay more than the present value of the dye.
Why, though, does Rashi explain the Gemara this way? Why does he not explain that the value of the dye depreciated, as the Ramban explains? Perhaps Rashi derives his explanation from the fact that the Gemara does not mention that if the dye is not considered present, the thief will have to pay based on the original value of the dye and not based on the present value. Until the Gemara gives this answer (and in its following answer, that the thief dyed a monkey with the dye), the Gemara assumes that the thief must pay the present value of the dye. If the whole point of this answer is that the thief must pay a different value, the Gemara should say so explicitly. This is why Rashi learns that the Gemara means simply that dyed wool is less valuable than wool alone and dye alone. (Perhaps even the Ramban does not mean that the Gemara is saying the value of dye depreciated, but rather that the Rif refers to a case in which the value of dye depreciated. The Ramban writes this in order to answer the question of the Ba'al ha'Me'or on the Rif.)
Why does the Gemara itself not suggest that the practical difference exists in a case in which the dye depreciates in value after it is stolen? Rabeinu Moshe Kazis points out that the Gemara indeed could have offered this case as a practical difference. Perhaps the Gemara does not offer this case as a practical difference because it seeks to keep the case simple. The Gemara wants to find a way to obligate the thief pay (when the dye is not considered present) because he did not return the full value of the dye, and not because he acquired it with a Shinuy and must return the original value of the dye (its value at the time that he stole it).

101b----------------------------------------101b

2) THE DEFINITION OF "BI'UR"
OPINIONS: The Gemara quotes a Beraisa which teaches that if a person dyes clothing with the dye from fruit of Shevi'is, the clothing must be burned.
Why must the clothing be burned? It is apparently because of the Halachah of Bi'ur, which requires that one destroy (Meva'er) fruit of the Shemitah year after the time that such fruit is no longer available in the field. (TOSFOS RABEINU PERETZ, ME'IRI; according to the RASHASH, this is also the intention of RASHI in DH Yesh Lahen Bi'ur; see following Insight.)
The Beraisa implies that Bi'ur means the destruction of produce (as in "Bi'ur Chametz"). However, the Tosefta (Shevi'is 8:4) states that at the time of Bi'ur, a person must take the Shevi'is fruit into the street and make it Hefker so that anyone may take it, and afterwards he may bring it back into his home and eat it until it is finished. This implies that Bi'ur means simply taking the fruit out of one's home (and making it Hefker), as in "Bi'ur Ma'aseros" (which is done in the fourth and seven year).
What is the meaning of Bi'ur?
(a) The RAMBAM (Hilchos Shemitah 7:1-3) explains that Bi'ur means that the produce becomes prohibited to be eaten and it must be burned or destroyed. This also seems to be the view of Rashi here (and in Yevamos (122a) and other places). Rashi writes that produce of Shevi'is is destroyed at the time of Bi'ur. How does Rashi, understand the Tosefta?
Rashi in Pesachim (52b, DH Mishum she'Ne'emar) explains that one destroys the fruit by placing it in a place that is Hefker, where it will be trampled by animals. (See also Rashi to Nidah 51b, DH Kol she'Yesh Lo, who explains that Bi'ur means to remove the fruit from one's home.)
Why does the Beraisa here teach that the produce must be burned at the time of Bi'ur? Perhaps Rashi maintains that only a garment must be burned, since it is not ruined by the trampling of animals. Fruit, on the other hand, may be placed in a public area where it will be trampled.
(b) TOSFOS in Pesachim (52b, DH Misba'arin), the RAMBAN (Vayikra 25:7), and the RASH (Shevi'is 9:8) explain that there is no requirement to burn or destroy produce of Shemitah at the time of Bi'ur. One simply must make the produce Hefker so that anyone may take it, and afterwards even the owner may reclaim it for himself and eat it for as long as he wants. The Ramban proves this from the Tosefta mentioned above and from the fact that produce of Shemitah does not appear in the list of Isurei Hana'ah (at the end of Maseches Temurah) which are either buried or burned.
According to these Rishonim, why does clothing dyed with the produce of Shemitah need to be burned? (MELECHES SHLOMO, Shevi'is 7:1)
The Ramban answers that if the owner did not make the produce Hefker before the time of Bi'ur, the produce becomes prohibited (perhaps only mid'Rabanan).
Alternatively, perhaps the Beraisa refers to produce of Shemitah which the owner did not make Hefker but treated like produce of other years. According to RABEINU TAM (cited by Tosfos to Sukah 39b, DH ba'Meh Devarim Amurim), such produce becomes Asur mid'Oraisa. According to the Ramban (Vayikra 25:5), it becomes Asur mid'Rabanan.
(c) The RA'AVAD (Hilchos Shemitah 7:3) writes that both opinions are correct. There are two different types of Bi'ur which must be done with fruit of Shevi'is. When the fruit of Shevi'is is no longer available in one particular city or location, every person who lives in that location must be Mafkir the fruit in his possession, or he must bring it to Beis Din to distribute. However, when a particular fruit is no longer available in one of the three regions of Eretz Yisrael (Yehudah, Galil, and Ever ha'Yarden; see Shevi'is 9:2), the fruit must be destroyed.
3) USING DYES OF "SHEVI'IS"
QUESTION: The Gemara quotes the Mishnah in Shevi'is (7:1) which states that the laws of Shevi'is and the laws of Bi'ur apply to "Sefichei Satis," plants from which dyes are made (see Background to the Daf, Bava Kama 101:20), and to the money which is paid for them.
RASHI explains that when the Gemara says that the laws of Shevi'is apply to them it means that one may not do business (Sechorah) with them because the Torah says "l'Ochlah," which teaches that the fruit must be eaten and not traded. One may not use these fruits for dye because such use is considered Sechorah. However, one is permitted to burn them before the time of Bi'ur because that is a use similar to eating, "l'Ochlah."
Rashi's words are perplexing. Why should dyeing a garment with fruit of Shevi'is be considered Sechorah, if one does so for his own personal use? Moreover, the Gemara immediately afterwards teaches that one is permitted to use dyes of Shemitah for dyeing clothing, since they are considered "Hana'asan u'Vi'uran Shaveh" -- the Shemitah produce is consumed before the benefit is derived from it (see Rashi DH Yatz'u Etzim). (When the Beraisa (end of 101a) teaches that clothing dyed with Shemitah produce must be burned, it refers to after the time of Bi'ur has passed.)
Moreover, how can Rashi permit one to burn fruit of Shemitah before the time of Bi'ur arrives on the grounds that burning is similar to eating? The Gemara immediately afterwards teaches that burning wood is not similar to eating fruit (and it therefore should be prohibited)! (REBBI AKIVA EIGER, MAR'EH KOHEN, YEFEH EINAYIM, MIKDASH DAVID to Zera'im 59:4)
A similar question may be asked on the words of Rashi later (beginning of 102a, DH Stam), where he writes that Sefichei Satis, which have Kedushah, may not be used after the time of Bi'ur even as firewood. This implies that before the Bi'ur they may be used for firewood, which contradicts the Gemara! (RASHASH, MAHARSHA in Mahadura Basra)
ANSWER: It seems clear that there is a typographical error in the words of Rashi, and that the words as they appear in our text must be reversed. The words of Rashi as they appear in our text are: "We may not do business (Sechorah) with them (plants of Shevi'is) because the Torah says 'l'Ochlah' and not for Sechorah, and it is forbidden to dye with them because such use is considered Sechorah. But we are permitted to burn them before the time of Bi'ur because that is similar to eating." Those of words of Rashi should read instead: "We may not burn them (plants of Shevi'is) because that is similar to Sechorah, but we are permitted to dye with plants of Shevi'is because dyeing is similar to eating" (as the Gemara explains). (The Mar'eh Kohen makes a different emendation in the words of Rashi.)
The cause for this error may have been the comment of Rashi earlier (end of 101a). When the Beraisa teaches that a garment dyed with Shemitah produce must be burned, Rashi writes that "one is prohibited to do Sechorah with fruit of Shevi'is," implying that dyeing clothes is similar to Sechorah. What does Rashi mean? In what way is dyeing comparable to Sechorah? Similarly, according to our suggested emendation in the words of Rashi, Rashi considers the act of burning firewood similar to an act of Sechorah, but in what way is burning similar to Sechorah?
The answer is that Rashi understands that the Isur of Sechorah is directly related to the Halachah of Bi'ur. When the Torah says, "l'Ochlah," it means that Shemitah produce must be eaten before the time of Bi'ur, and it is for that reason that one may not do business with Shemitah produce; one benefits from it without destroying it and he might come to use it after the time of Bi'ur. For this reason, Rashi includes in the category of Sechorah any use of Shemitah produce which is either after the time of Bi'ur or which is before the time of Bi'ur but one derives benefit from the fruit at a time other than the moment at which the fruit is consumed. This is clear from Rashi later (102a, DH l'Toch) who writes that washing clothes with wine of Shevi'is is prohibited because of Sechorah. Why does Rashi not write that it is prohibited because it is not "Hana'asan u'Vi'uran Shaveh," as the Gemara explains (REBBI AKIVA EIGER)? The answer is that Rashi puts anything which is not "Hana'asan u'Vi'uran Shaveh" into the category of Sechorah because it might cause a person to benefit from the fruit of Shevi'is after the time of Bi'ur. This is also clear from Rashi in Sukah (see Insights to Sukah 39:2).
Accordingly, this is what Rashi means here when he writes that one is prohibited from burning wood of Shevi'is because of Sechorah (according to our emendation). This is also the intention of Rashi means earlier (101a) when he writes that one must burn a garment dyed with Shevi'is fruit after the time of Bi'ur because one may not do Sechorah with fruit of Shevi'is.
In short, the Isur of Sechorah is the source for all of the Halachos of Bi'ur of fruits of Shemitah.
What does Rashi later (beginning of 102a) mean when he writes that dye plants of Shevi'is may not be burned as firewood after Bi'ur, which implies that before Bi'ur they may be used in such a manner? It seems clear from Rashi that the words "even for fuel" are out of place and they belong three words earlier. Rashi is saying that plants which normally are used to produce dyes are Kadosh with Kedushas Shevi'is to the extent that even if one picks them with intent to use them as fuel, they still retain the Kedushah of Shevi'is and cannot be used after the time of Bi'ur. This is the context in which these words appear in Rashi. (M. Kornfeld)