1) AGADAH: THE MEANING OF "TO'EVAH," "TEVEL," and "ZIMAH"
QUESTION: At the wedding of Rebbi's son, Bar Kapara agreed to relate three lessons to Rebbi if Rebbi would dance in front of him (see SHALMEI NEDARIM and BEN YEHOYADA). The three lessons which he taught Rebbi were the meanings of the words, "To'evah" (Vayikra 20:13), "Tevel" (18:23) and "Zimah" (20:14). Bar Kapara taught that "To'evah" means "To'eh Atah Bah," "Tevel" means "v'Chi Tavlin Yesh Bo," and "Zimah" means "Zu Mah Hi."
Why did Bar Kapara teach Rebbi specifically these three lessons at the wedding of Rebbi's son?
ANSWER: The MAHARAL (in Chidushei Agadah) explains that during a time of Simchah a person is more vulnerable to the temptations of physical lusts (see Berachos 31a). (Perhaps this is the reason why Rebbi refrained from deriving any type of pleasure or joy from this world; he sought to avoid being enticed to follow physical lusts.)
Bar Kapara sought to add to the joy of the wedding, but at the same time he wanted to prevent the joy from leading to licentiousness. Hence, when he made Rebbi dance as an expression of joy, he simultaneously taught that the desires of this world are meaningless and worthless. "Zimah" means "Zu Mah Hi" -- there is nothing in it; it is all an illusion. "To'evah" means "To'eh Hi Bah" -- one who follows his lusts errs and goes wayward. "Tevel" means "v'Chi Tavlin Yesh Bah" -- is there any real value to the material pleasures which a person pursues so tirelessly in this world? Rather, a person should rejoice in and derive pleasure from a Mitzvah and refrain from all pleasures of Olam ha'Zeh that are not related to a Mitzvah.
2) THE DIFFERENCE BETWEEN "MA'ASEH KEDEIRAH" AND "HA'NA'ASEH B'KEDEIRAH"
QUESTION: The Mishnah says that when a person makes a Neder to prohibit himself from eating "Ma'aseh Kedeirah," he is prohibited from eating "Ma'aseh Raschasa," food boiled in a pot. If he makes a Neder to prohibit "ha'Yoreh l'Kedeirah," he is prohibited from all foods cooked in a pot.
The Gemara cites a Beraisa which distinguishes between "ha'Na'aseh b'Kedeirah" and "ha'Yored l'Kedeirah" differently. "Ha'Na'aseh b'Kedeirah" implies any food that was completed by being cooked in a pot. The Beraisa makes no mention of "Ma'aseh Raschasa."
Why, though, should a Neder of "ha'Na'aseh b'Kedeirah" differ from a Neder of "Ma'aseh Kedeirah" if they both imply the same type of food? Moreover, the Beraisa cited later (at the end of the Amud), which discusses "Ma'aseh Tanur," clearly implies that there is no difference between "ha'Na'aseh" and "Ma'aseh"!
(a) TOSFOS and the ROSH (in his second explanation) explain that the Mishnah and the Beraisa teach the same thing, but in different words. The Beraisa says that the difference between "ha'Na'aseh b'Kedeirah" and "ha'Yored l'Kedeirah" is that "Na'aseh" means that the food was completed in a pot, and it does not matter whether it started cooking in a pot or in something else (such as in a pan), and "ha'Yored" means that it started cooking in a pot, and it does not matter whether it was completed in a pot or in something else.
When the Mishnah says that when one makes a Neder to prohibit "Ma'aseh Kedeirah" he is prohibited from "Ma'aseh Raschasa," it means that he is prohibited from food that was brought to a boil and completed in a pot. When the Mishnah continues and says that when one makes a Neder to prohibit "ha'Yored l'Kedeirah" he is prohibited from any food that was "cooked in a Kedeirah," it means that he is prohibited from food which began cooking in a Kedeirah, even though its cooking was not completed in a Kedeirah (but in a pan).
(Tosfos' text of the Mishnah as quoted on 51a does not include the words, "Asur b'Chol ha'Na'aseh b'Kedeirah." Rather, his Girsa is the text of the Mishnah as it is expressed on 49a, "Asur b'Chol ha'Misbashlin b'Kedeirah.")
(b) The RAN quotes the Yerushalmi which says that "Ma'aseh Raschasa" is unrelated to being completed in a pot. Rather, it refers to the type of food which needs to be boiled for a long time. How, then, does the Ran reconcile the Mishnah with the variant ruling of the Beraisa?
The Ran apparently maintains that when one makes a Neder by saying "ha'Na'aseh b'Kedeirah," he is prohibited from foods that meet both of two criteria: the food must be completed in a Kedeirah, and it is the type of food that is cooked copiously ("boiled"). The Mishnah teaches one criterion (that the words "ha'Na'aseh b'Kedeirah" include a food cooked copiously), and the Beraisa adds another criterion: in order to be included in the Neder, the food must be one which is completed in a Kedeirah. (See also MEFARESH on the Mishnah, 51a.)
The Ran's explanation here seems consistent with his explanation of the phrase in the Beraisa, "ha'Yored l'Kedeirah." The Ran writes that "ha'Yored l'Kedeirah" refers to anything that was ever cooked in a Kedeirah, whether its cooking started there or finished there. Accordingly, "ha'Yored" is a more inclusive term than "ha'Na'aseh." Just as the Beraisa teaches that "ha'Yored" adds to the Neder foods cooked in a Kedeirah at any point of their preparation, the Mishnah adds that "ha'Yored" adds to the Neder even foods that are not abundantly cooked. In contrast, the phrase "ha'Na'aseh b'Kedeirah" in a Neder limits the prohibition to foods cooked abundantly.
Tosfos, on the other hand, maintains that "ha'Yored" (in the Beraisa) is as limiting as "ha'Na'aseh." "Ha'Yored" means that the cooking was started in a Kedeirah (and not that it was in a Kedeirah at any point of its preparation), and "ha'Na'aseh" means that the cooking was completed in a Kedeirah. If "ha'Na'aseh" limits the Neder to foods cooked abundantly, then "ha'Yored" must also be limited to foods cooked abundantly. Therefore, the Mishnah cannot be teaching that "ha'Yored" includes more types of food that "ha'Na'aseh."
According to the Ran, however, why does the Beraisa state that a Neder of "ha'Yored l'Tanur" prohibits only bread, while "Kol ha'Na'aseh b'Tanur" prohibits all foods made in a Tanur? According to the Ran, "ha'Yored" is a more inclusive term and should include more items that "ha'Na'aseh."
The reason why "Kol ha'Na'aseh b'Tanur" includes more foods is that the person used the word "Kol" ("all"), which extends the meaning of his Neder. The same would apply if he would say, "Kal ha'Yored l'Tanur"; such a Neder would include all foods made in a Tanur. The reason why the Beraisa says "Kol ha'Na'aseh" and not "Kol ha'Yored" is to teach that even when one says "Kol ha'Na'aseh" and uses a more limiting term ("ha'Na'aseh"), nonetheless the word "Kol" makes it all-inclusive.
3) SMALL FISH AND BIG FISH
The Gemara initially suggests that "Dag" refers to large fish and "Dagah" refers to small fish. The Gemara rejects this suggestion based on the verse that discusses the plague of Dam in Mitzrayim. The verse says that the "Dagah in the river (Ye'or) died" (Shemos 7:21). It does not make sense that only the small fish died and not the large fish. It must be that "Dagah" includes fish of any size.
The ROGATCHOVER GA'ON (see Tzafnas Pane'ach, Shemos 17:21, and Mahadura Tinyana 14a) suggests that the Gemara's initial assumption that "Dagah" refers only to small fish may have been based on the following consideration.
The plague of Dam was intended to affect only the Egyptian people and not public property. Flowing rivers are considered public property. As such, the waters within them are not limited to the possession of the people who live in the area of those rivers (Beitzah 39a, Eruvin 45b; see also Avodah Zarah 47a).
Hash-m did not turn the waters of the rivers of Mitzrayim into blood. Rather, he told Aharon to hit the waters of the "Ye'or" with his staff and to turn its waters into blood (Shemos 7:17, 20). The word "Ye'or" refers to a man-made irrigation canal (Bava Metzia 103b). A canal dug by an individual becomes the private property of that person (Tosfos to Bava Kama 81a, DH u'Ma'ayan). Although the verse says that the "rivers and lakes will also be of blood" (7:19), it does not say that they turned into blood. Rather, they became full of blood as a result of the blood in the private canals that flooded into them and polluted them. (Accordingly, the verse says "v'Hayu l'Dam" with regard to the rivers, but with regard to the canals the verse says "v'Nehepchu" -- "they were transformed" into blood.)
This explains why only the small fish died. The Mishnah in Gitin (59b) teaches that animals caught in a private trap or pond but on which no Kinyan was actually made (they were not picked up by the owner of the trap) are considered Hefker, mid'Oraisa. The Chachamim enacted that they belong to the owner of the trap only because of "Darchei Shalom." According to the Mishnah there, the fish in the private canals in Mitzrayim should not have been affected by the plague of Dam since they were not the property of the individual owners but were public property. However, the Yerushalmi in Gitin (5:9) says that the law of the Mishnah in Gitin applies only to large fish or animals, but small fish or animals are considered the possession of the owner of the trap or net. This is why the plague of Dam did affect the small fish -- those fish were the possession of individual Egyptians.
The Rogatchover Ga'on suggests that although the Gemara here concludes that the big fish must have died as well, the Yerushalmi argues with the Gemara here. Alternatively, the Gemara here means that the big fish eventually died because of the pollution to their environment or because of the ecological imbalance (caused by the death of the small fish); they did not die, however, as a direct result of the blood. The small fish, on the other hand, died immediately as a result of the blood. The Torah uses the word "Dagah" to imply that the primary victim of the plague of Dam was the small fish, while the ramification for the big fish was only secondary.