1) THE PROBLEM WITH INVESTIGATING PRE-CREATION
QUESTION: The Gemara says that one may not inquire what existed before the world was created. The Gemara compares this proscription to a king who built his palace on top of a garbage heap. The king does not want people to discuss what was there before the palace.
The Gemara's comparison is difficult to understand. What disgrace would there be if one mentions what existed before the world was created? Nothing disgraceful existed, because nothing existed! In what way is such an inquiry comparable to people who discuss the garbage heap which existed in the place of the king's palace?
ANSWERS:
(a) The MAHARSHA answers that the disgrace in inquiring what existed before the world was created is the very suggestion that something else existed before the world was created. The analogy is not entirely accurate, because in the Gemara's case of one who inquires what existed before the world was created, the disgrace is the very suggestion that something existed, and not that something disgraceful actually existed.
(b) The Maharsha quotes the YEFEH MAR'EH on the Yerushalmi who explains the Gemara based on the words of the RAMBAN in the beginning of Parshas Bereishis. The Ramban writes that when Hash-m created the world, He first created a form of matter or energy called "Hiyuli" (from the Greek "hyle," or "matter"). Hash-m created the world only after He created this elemental matter or energy and formed the world from it. The "Ashpah" in the analogy is this "Hiyuli," which was the unfinished, unformed matter or energy. Since it lacked form, it is a disgrace to delve into it.
(c) RAV YAKOV EMDEN explains that the Gemara alludes to the Midrash (Bereishis Rabah 3:7) which states that Hash-m created and destroyed a number of worlds before He created this world and decided to keep it. The earlier worlds which did not satisfy Him are like the "Ashpah" on which the king built his palace.
(d) RAV MOSHE FEINSTEIN zt'l in DARASH MOSHE (cited by the YOSEF DA'AS) explains that it is a disgrace to Hash-m when a person seeks to explore the premundane facets of the world's existence in order to discover evidence for the hand of Hash-m in the design of the world, when that evidence is readily available in everything that exists in the natural world today. The fact that Hash-m created the world is evident in the infinitely brilliant design of every object that exists today. The Gemara compares it to praising a king for what he built his palace on, when there are many greater things in the day-to-day life of the kingdom for which the king prefers to be praised.
2) THE PROHIBITION AGAINST INQUIRING INTO FOUR THINGS
QUESTION: The Mishnah (11b) states that "anyone who looks into four things is better off having not been created: what is above, what is below, what is before, and what is after."
RASHI there explains that these four things are spatial: "what is above" refers to what is above the heads of the heavenly beings; "what is below" refers to what is below the heavenly beings; "what is before" refers to what is to the east of the "heavenly separation" outside of the world, and "what is after" refers to what is to the west.
Why does Rashi explain that all four of these things refer to spatial elements? The Gemara here clearly understands "what is before" and "what is after" as references to temporal elements -- what existed before the world was created and what will be after the world ceases to exist. Why does Rashi on the Mishnah give a different explanation from that which the Gemara itself gives? (TOSFOS)
ANSWER: RAV YAAKOV D. HOMNICK (in MARBEH NEDAVAH) proposes the following explanation for the words of Rashi. The Mishnah begins with a list of Torah subjects which may not be taught in groups of various sizes. The subject of Arayos may not be expounded with a group of three, Ma'aseh Bereishis with two, and Ma'aseh Merkavah with one. The second topic of the Mishnah are the four aspects of the world which a person may not explore. The third topic is "one who does not have mercy on the honor of His Creator is better off having not been created."
The Gemara (11b) initially assumes that the Mishnah is describing a prohibition in the laws of learning Torah. Hence, it assumes that when the Mishnah says that Arayos may not be expounded with three people, it means three people learning together, one expounding together with the other two. The Gemara concludes that the Mishnah is describing a prohibition in the laws of teaching Torah -- what the Rebbi may not teach and what the Talmid may not ask. Thus, the Mishnah means that one may not expound the laws of Arayos to three people.
Rashi on the Mishnah therefore explains the Mishnah according to the Gemara's initial assumption: it is discussing a prohibition in the laws of learning (and not in the laws of teaching) Torah. That is, it is discussing what topics one may learn or may not learn. According to the Gemara's initial assumption, when the Mishnah teaches that one may not look into four things (what is above, what is below, etc.), it means that there are certain topics of information which one may not learn. The information about those topics exists in the world, but one is prohibited to study it. Hence, Rashi explains that this information refers to the things which are above and below the world, and to the east and west of the world.
According to the Gemara's conclusion, however, the Mishnah is discussing the laws of teaching and not the laws of learning. The Mishnah lists the topics which one may not even inquire about from one's teacher -- the inquiry itself is prohibited, and not just the learning. By asking for information about things outside of the realm of this world which have not been revealed to man, a person shows a lack of respect to Hash-m. According to this understanding of the Mishnah, the Mishnah is saying that the information about which one may not inquire does not exist in the world; it is not known at all, and thus one is prohibited to inquire about it. This is in contrast to the initial understanding of the Gemara, according to which the information discussed in the Mishnah does exist in the world but one is not permitted to delve into it.
This approach explains why Rashi on the Mishnah (DH Arba'ah Devarim) writes, "[the four things] which are about to be explained." Why does Rashi need to write that the Mishnah is about to explain these four things, when this is apparent from the very next words in the Mishnah? The answer is that Rashi is alluding to the Gemara's initial understanding of the Mishnah. The Gemara initially assumes that the Mishnah lists the topics of information which exist in the world but which may not be studied, and thus Rashi says that the Mishnah is going to list those topics of information. According to the Gemara's conclusion, however, the four items in the Mishnah's list are not known topics of information, but rather they are questions -- one may not inquire into these four unknowns ("What is above?", "What is below?", etc.).

16b----------------------------------------16b

3) WHO WAS THE NASI AND WHO WAS THE AV BEIS DIN
QUESTIONS: Rebbi Meir and the Chachamim dispute whether, generations earlier, Yehudah ben Tabai was the Nasi and Shimon ben Shetach the Av Beis Din, or vice versa. The Gemara cites a Beraisa as proof for the opinion that Yehudah ben Tabai was the Nasi. The Beraisa relates that a certain case came before Yehudah ben Tabai who ruled that a single Ed Zomem must be killed, and his ruling was carried out in practice. Shimon ben Shetach pointed out to him his tragic mistake -- Edim Zomemim are killed only when both witnesses are proven to be scheming, but not when only one of them is found to be an Ed Zomem. In remorse that he had put to death a single Ed Zomem, Yehudah ben Tabai accepted upon himself never again to issue a Halachic ruling except in the presence of Shimon ben Shetach.
The Gemara says that from this incident it is evident that Yehudah ben Tabai must have been the Nasi, a position invested with more authority than the Av Beis Din. Had Yehudah ben Tabai been the Av Beis Din, he would not have been able to rule on his own until now without Shimon ben Shetach's consent. It must be that Yehudah ben Tabai was the Nasi and Shimon ben Shetach the Av Beis Din.
The Gemara refutes this proof and says that it is possible that Yehudah ben Tabai indeed was the Av Beis Din and had less authority than Shimon ben Shetach. He never ruled in the presence of Shimon ben Shetach even before his oath. Rather, before the incident with the Ed Zomem, Yehudah ben Tabai "joined others" in ruling without Shimon ben Shetach's consent, and now he accepted upon himself never even "to join others" to rule without Shimon ben Shetach.
(a) The Gemara's refutation of the proof from the Beraisa is problematic. First, what difference did it make if Yehudah ben Tabai (as Av Beis Din) would join others? He still was not entitled to rule in the presence of the Nasi, Shimon ben Shetach, without permission. When the Gemara earlier says that if he had less authority than Shimon ben Shetach then he could not have ruled without Shimon ben Shetach, it means that he could not have even joined a Beis Din to rule without Shimon ben Shetach. What, then, did Yehudah ben Tabai gain by accepting upon himself never to join with others to rule without Shimon ben Shetach, if he could not join others to rule without him in the first place?
(b) RASHI explains that according to the Gemara's refutation of the proof, Shimon ben Shetach was not present (in the city) when Yehudah ben Tabai killed the Ed Zomem, because had he been present Yehudah ben Tabai would not have been allowed to rule since he had less authority. Why, then, does the Gemara not answer simply that his oath was that he would no longer rule when Shimon ben Shetach was out of town (so that he would never commit another tragic error)? By making such a commitment, he would correct the mistake he made by ruling while Shimon ben Shetach was absent.
ANSWERS:
(a) There are several ways to understand how Yehudah ben Tabai would have issued a Halachic ruling (before his oath) without Shimon ben Shetach and without joining others.
1. Although Yehudah ben Tabai had less authority than Shimon ben Shetach and could not rule without him, before his oath he would have judged with another Nasi other than Shimon ben Shetach (in the event that Shimon ben Shetach died or a new Nasi took his place). Alternatively, he would have ruled whenever he received Shimon ben Shetach's permission. After the incident with the Ed Zomem, he accepted upon himself never to rule without Shimon ben Shetach; if a new Nasi would be appointed, Yehudah ben Tabei would not issue any rulings with that Nasi. Alternatively, he would not rule even if he had permission from Shimon ben Shetach to rule without him.
2. TOSFOS explains that Yehudah ben Tabai accepted upon himself not to join the majority of Chachamim when their opinion differs from that of the Nasi, even when the Nasi is present.
(b) There are several reasons for why the Gemara does not say simply that Yehudah ben Tabai accepted upon himself to judge only when Shimon ben Shetach was in town.
1. The NETZIV explains that it is unreasonable to suggest that the Beis Din would be closed simply because the Nasi is out of town. (This answer is difficult to understand, because it seems obvious that other arrangements would be made for Beis Din to convene without its Av Beis Din (Yehudah ben Tabai) when the Nasi is out of town. For example, another Av Beis Din would be appointed in the interim.)
2. The Gemara means that not only did Yehudah ben Tabai accept upon himself not to judge even when Shimon ben Shetach is not present, but he even accepted upon himself not to join others in judgment when Shimon ben Shetach is present (for example, he accepted upon himself not to join a majority against Shimon ben Shetach).
This answer is also difficult to understand. How does the Gemara know that he accepted upon himself the additional oath not to join with others? In order for the Gemara to refute the proof that Yehudah ben Tabai was the Nasi, it would have sufficed to say that he accepted merely not to rule when Shimon ben Shetach was out of town.
Perhaps the Gemara understands that Yehudah ben Tabai intended to make this additional oath because he said, "I will judge only with Shimon ben Shetach." If he meant that he would not judge when Shimon ben Shetach was out of town, then he should have said, "I will not judge without Shimon ben Shetach." By saying, "I will judge only with Shimon ben Shetach," he implied that even when Shimon ben Shetach is in town, he would judge only in Shimon ben Shetach's presence. (M. Kornfeld)
3. The ME'IRI offers an entirely different approach to the Gemara's refutation of the proof that Yehudah ben Tabai was a Nasi. His approach answers both questions. The Gemara does not infer from Yehudah ben Tabai's words that he used to judge when Shimon ben Shetach was in town. Rather, it infers from his words what he accepted to do; he accepted to judge only when Shimon ben Shetach is present (in town), so that if he makes a mistake Shimon ben Shetach will correct him. The Gemara asks that if Shimon ben Shetach is in town, Yehudah ben Tabai may not judge at all because one is not permitted to issue a ruling in front of his Rebbi.
The Gemara answers that his oath was that he would judge only if Shimon ben Shetach is both in town and is sitting on the court (in which case it is permitted for the Talmid to issue a ruling in the presence of his Rebbi).
Apparently, the Me'iri's Girsa was that of the DIKDUKEI SOFRIM who adds a few words to the Gemara. According to his text, Yehudah ben Tabai accepted upon himself that he "will not join others [to judge] except with Shimon ben Shetach." That is, he accepted to judge only when joined by Shimon ben Shetach. His oath was that he would not convene a court when the Nasi is out of town. (Accordingly, the Gemara indeed gives the answer which we suggested (in question (b) above).)
(RASHI (DH u'Mai Kibel) clearly disagrees with the Me'iri's approach. Rashi writes that the proof is from what Yehudah ben Tabai used to do before his oath. However, the Dikdukei Sofrim points out that from the text of Rashi in the Ein Yakov it appears that these words were not written by Rashi, and thus Rashi indeed may have learned like the Me'iri.)

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