1) "MA'AVIRIN AL HA'OCHLIN"
QUESTION: The Gemara proposes that whether a "Siman he'Asuy li'Dares" is a Siman is a Machlokes Tana'im between Rebbi Yehudah and the Tana Kama, who argue in the Mishnah about whether one who finds a "Kikar uv'Socho Ma'os" must announce his find. The Gemara suggests that both Rebbi Yehudah and the Tana Kama maintain "Ma'avirin Al ha'Ochlin," but Rebbi Yehudah maintains that a "Siman he'Asuy li'Dares" is a Siman, and therefore the owner does not lose hope of retrieving the loaf because he knows he has a Siman on it. The Tana Kama maintains that a "Siman he'Asuy li'Dares" is not a Siman and the owner despairs because he does not rely on the Siman on his object.
Why does the Gemara assume that if the Halachah is "Ma'avirin Al ha'Ochlin," the owner will give up hope and assume that the Siman on the loaf will be destroyed?" Both RASHI and TOSFOS (DH Ein Ma'avirin) explain that "Ma'avirin" does not mean that people step on the bread, but that people pass by it and do not pick it up. (Tosfos proves this from the Gemara in Eruvin.) Even if people do not pick up the bread, the Siman on the bread will not be destroyed because neither Jews nor Nochrim step on bread out of fear of Kishuf, as the Gemara earlier says. Also, the Gemara earlier establishes that the Mishnah refers to objects found in places where animals are not normally found, and thus there is no concern that the Siman will be destroyed by animals. The Gemara here clearly is not retracting one of its original assumptions (that the Mishnah assumes that people are afraid of Kishuf, or that the Mishnah refers to a place where animals are found), because in that case it would not be necessary to understand that the Tana'im maintain "Ma'avirin Al ha'Ochlin." Even if the Tana'im agree with the opinion of "Ein Ma'avirin Al ha'Ochlin," the Tana Kama still would maintain that the owner will have Ye'ush, either because of the presence of animals or because of the presence of Nochrim, as the Gemara says earlier. (MELO HA'RO'IM)
ANSWERS:
(a) The RITVA addresses this question and explains that when the Gemara here says "Ma'avirin Al ha'Ochlin," it does not use the phrase with its usual connotation (as it uses it at the beginning of the Sugya). Rather, it means that people actually step on the food.
According to the Ritva, the Gemara means either that people are not afraid of Kishuf and therefore they step on the bread, or that animals are common in that area and they step on the bread. The Gemara does not refer to the Halachic issue of whether one must pick up the bread as soon as he sees it. The Gemara uses the phrase "Ma'avirin Al ha'Ochlin," even though this is not its usual meaning, since it uses that phrase earlier.
(b) The MELO HA'RO'IM answers that the term "Ein Ma'avirin Al ha'Ochlin" may have the same connotation here as it has earlier: that one who finds a loaf of bread on the ground is not permitted to leave it there, but rather he must pick it up. The Gemara here, however, associates the opinion that the owner will have Ye'ush with the opinion of "Ma'avirin Al ha'Ochlin." If one is permitted to leave food on the ground, then even though people do not intentionally step on the loaf because of their fear of Kishuf, and animals are not commonly found in the area, nevertheless the loaf will be left on the ground for a long time. Once it remains on the ground long enough, it eventually will be trampled either by Ketanim and Shotim who are not worried about Kishuf or by the animals that infrequently pass through the area.
This may explain why Rashi emphasizes that "Ein Ma'avirin Al ha'Ochlin" does not mean that one is not permitted to step on food, but rather that one must pick up a loaf that he finds on the ground and he may not leave it there. Why does Rashi need to emphasize this here? If his only source for this interpretation is the Gemara in Eruvin (as Tosfos says), it is not necessary for Rashi to make a point of it here.
It seems that Rashi is bothered by the question of the Melo ha'Ro'im. If "Ma'avirin" means that one may step on the loaf, then why does the Gemara suggest, according to the Tana Kama who argues with Rebbi Yehudah, that if the Halachah is "Ma'avirin Al ha'Ochlin" the owner will have Ye'ush because the Siman on the loaf is "Asuy li'Dares"? Why should that be so? Even if the Halachah permits one to step on the loaf, people will not step on it because of their fear of Kishuf. The Gemara should add that the owner has Ye'ush because people are not afraid of Kishuf, and therefore they will step on the loaf. If people are afraid of Kishuf, the owner will never have Ye'ush, as the Gemara earlier says, even if the loaf was left in Reshus ha'Rabim for an indefinite period of time, because no one will come to step on it.
This is what forces Rashi to explain that "Ein Ma'avirin Al ha'Ochlin" really means that one is not permitted to leave a loaf of bread on the ground. The Gemara means that if the loaf is left there indefinitely, the Siman certainly will be trampled (by Ketanim or Shotim). The Siman will remain intact only because the first Jew who sees it will pick it up. That is why the Gemara suggests that if the Halachah is "Ma'avirin Al ha'Ochlin," and Jews are not commanded to pick up the loaf, then one may assume that the original owner had Ye'ush because he knows that the Siman eventually will be trampled by Ketanim and Shotim.

23b----------------------------------------23b

2) THE "SIMAN" OF A SEALED BARREL
QUESTIONS: The Gemara points out a contradiction between the Mishnah, which states that a person who finds lost barrels of wine or oil must announce his find, and the Beraisa, which states that the finder may keep them. Rebbi Zeira answers that in the case of the Mishnah, the barrels were previously opened and then resealed ("Rashum"). In the case of the Beraisa, the barrels were opened and not resealed; they are merely covered with a lid that is not sealed shut.
RASHI (DH b'Rashum) explains the significance of a seal as follows. In general, when the Ba'alei Batim who produce the wine are ready to sell their wine (in Shevat or Nisan), they remove the covers of their barrels in order to allow the storeowners (who will purchase the wine) to taste the wine, and then the storeowners close the barrels and seal them shut with a sealant. This seal is called a "Roshem." In the case of the Mishnah, the Roshem on the barrel creates a Siman because some storeowners make a Roshem before they take the barrel, while others take the barrel with intent to sell the contents immediately and they do not bother to reseal it.
Rashi's words imply that the Siman is the fact that the barrel has a Roshem. The owner can identify the barrel by the fact that it has been resealed and was not left open. This is difficult to understand for two reasons.
(a) Many of the barrels that the storeowners take are resealed. Why, then, should a person who lost a barrel be able to identify his barrel by the mere fact that it was resealed? How can that be an identifying mark if many barrels are resealed? (RITVA, CHOCHMAS MANO'ACH)
(b) If a sealed cover on a barrel is considered a Siman, then an unsealed cover on a barrel should also be a Siman! Why does the Beraisa say that if one finds a barrel that is open (i.e. not sealed) he may keep it because it has no Siman? (RASHASH, MAHARAM SHIF)
ANSWER: TOSFOS (DH b'Rashum) and all of the other Rishonim argue with Rashi and explain that a Roshem does not refer to the mere fact that a barrel is sealed. Rather, it refers to every person's unique seal. Each Roshem is made slightly differently and, therefore, the Siman is not the fact that the barrel has a Roshem, but rather the way the Roshem looks. The fact that there is a Roshem is not a Siman since most barrels have a Roshem.
The RASHASH suggests that Rashi does not disagree with Tosfos on this point. Rashi also means that the barrel has a Siman because of the distinct appearance of its Roshem, and not just because of the fact that the barrel has a Roshem.
What does Rashi mean when he writes that a Roshem is a Siman "because there are some people who seal their barrels with a Roshem, and some who leave their barrels open in order to sell immediately"? Perhaps there is an error in our version of Rashi, and instead of the words "because there are some people...," the text should say "and there are some people..." ("v'Yesh" instead of "she'Yesh"). Alternatively, the words beginning with "she'Yesh..." may belong at the end of the following comment of Rashi, which explains the word "b'Pasu'ach" in the Gemara.
However, why does Rashi not emphasize (as Tosfos does) that each person seals the barrel in a different manner? After all, that is the essential component of the Gemara's answer. Perhaps Rashi is bothered by the question of Tosfos (in DH Abaye): why does Abaye argue with Rebbi Zeira and maintain that a Roshem is not a Siman? Tosfos there answers that the Roshem is made by the Ba'al ha'Bayis who produced the wine, but the barrels are usually lost by the storeowners who purchase them. Since many storeowners purchase barrels from the same Ba'al ha'Bayis, a Roshem cannot be an adequate Siman for the storeowner to prove that the barrel belongs to him and not to any of the other purchasers. Rashi, however, may have a different answer to this question.
It seems that Rashi and Tosfos argue with regard to who makes the Roshem. Tosfos maintains that the Ba'al ha'Bayis makes the Roshem. Rashi may understand that according to that approach, it should be obvious that the Roshem is not a Siman for the storeowner, even according to Rebbi Zeira (just as the Kikaros Shel Nachtom, loaves made by a professional baker, have no identifying mark that the purchaser can give, since many people purchase their bread from a single baker; see RASHASH on the Mishnah, 21a). Rashi therefore understands that the storeowner who purchases the barrel is the one who makes the Roshem (see end of Rashi DH b'Rashum). The storeowner can identify the barrel as his own based on the unique Roshem that he made. Why, then, does Abaye argue that the Roshem is not a valid Siman? Perhaps Rashi understands that the storeowners do not intentionally make identifying marks on all the barrels that they sell. Rather, they can give general Simanim which show that they were the ones who closed the barrels (for example, they can say that a lot of tar or mortar was used, or that the barrel was sealed neatly, or they can say how far down on the barrel the sealant reached, etc.). Abaye maintains that this is not an adequate Siman, since it is possible that two people happened to seal their barrels in the same way, while Rebbi Zeira maintains that such a Siman is an acceptable form of identification. This would explain why Rashi does not emphasize that every Roshem is made differently -- since the differences between the various types of Roshem are not intentional. (This is not a "Siman ha'Ba me'Elav" because it is externally visible, as Tosfos writes on 23a, DH Siman.)
3) LOCATION AS A "SIMAN"
QUESTION: The Gemara discusses whether or not the location (Makom) in which an object is found is a Siman. It attempts to prove from the Beraisa, which states that one who finds barrels of wine or oil may keep them, that the location is not a Siman. The Gemara rejects the proof because the case of the Beraisa may be where the barrels are found on the river bank. In such a case, the place where they are found is not a Siman because many people leave their barrels on the river bank. The Gemara states that the river bank is not a Siman because just as one person left a barrel on the river bank, someone else may have left a barrel there as well.
The Gemara presents another version of this statement. It asks why the Rabanan say that Makom is not a Siman, and it answers that just as the claimant might have left a barrel in a certain place, someone else might also have left a barrel in the same place.
It seems that the two versions disagree with regard to the general question of whether Makom is a Siman. According to the first version, Makom is a Siman in general, but when that Makom is the river bank it is not a Siman. According to the second version, Makom is never a Siman. However, RASHI (DH Ika d'Amri) writes that the difference between the two versions is that according to the second version, even if the owner describes the exact place where the barrel was found, it is not a Siman. The words of Rashi imply that there is no debate as to whether a Makom is a Siman in general. Rather, the only issue about which the two versions disagree is whether Makom is considered a Siman if a barrel is found on the river bank but the owner can identify exactly at which place on the river bank it was found.
Why does Rashi explain the Gemara in this manner, and not in the more obvious way?
ANSWER: RAV BETZALEL ASHKENAZI (in the Shitah Mekubetzes) explains that Rashi does not accept the possibility that the second version maintains that Makom is not a Siman, because the Gemara earlier (23a) concludes in accordance with Rava that Makom is a Siman. Therefore, Rashi explains that the second version is not discussing whether Makom in general is a Siman, but whether the owner's ability to cite a specific location along the river bank is considered a Siman. (Some Rishonim have a Girsa in the Gemara in which the second version also asks why the river bank is not a Siman.)
Apparently, according to Rashi the entire Sugya is a discussion of this very point. Rav Bivi's original question is not whether Makom is considered a Siman in general; the Gemara has already quoted a dispute between Rabah and Rava on that point. Rather, the question of Rav Bivi is whether a specific location in an area where many people leave their barrels is considered a Siman. Rav Bivi reasons that perhaps even if Makom is normally not a Siman, when the owner identifies an exact location, that is considered a Siman. On the other hand, perhaps even if Makom normally is a Siman, when the barrel is found in an area where many barrels are placed, even an exact location does not suffice as a Siman. The Gemara tries to prove from the Beraisa that even an exact location is not a Siman, since the Beraisa teaches that if one finds barrels of wine he may keep them. The Beraisa implies that even if the owner knows exactly where the barrels were found, this is still not a Siman because they were found in an area where many barrels are placed. The Gemara rejects the proof with the argument that the Beraisa allows the finder to keep the barrel only if the original owner identifies its location in general as the bank of the river, but he does not give an exact point along the river where the barrel was found. The Beraisa may agree, however, that if the owner can identify the exact spot on the river bank where the barrel was found, it must be returned to him.