1) THE PROHIBITION AGAINST BUILDING CERTAIN TYPES OF STRUCTURES WITH NOCHRIM
OPINIONS: The Mishnah states that we may not join Nochrim in building a "Basilki," "Gardom," "Itztadya," or a "Bimah."
What exactly are these structures, and why is one prohibited from building them together with Nochrim?
(a) The RA'AVAD and the RAMBAM (in Perush ha'Mishnayos here) explain that these structures are generally built for purposes of Avodah Zarah. The Rambam writes that these were chairs and platforms built in honor of idols and for use by the idols themselves.
Since these structures are used for purposes of Avodah Zarah, a Jew is forbidden from taking part in their construction.
(b) RASHI explains that a "Basilki" and a "Bimah" are towers with platforms, used by the Nochrim for carrying out death sentences by pushing people to their deaths from them. A "Gardom" is a courthouse in which trials of capital punishment take place. An "Itztadya" is a stadium which hosted the sport of having wild bulls gore people to death. Other Rishonim (see below) seem to learn like Rashi.
Rashi (DH Bimah) explains that the reason why a Jew may not join a Nochri in building such structures is that all of these structures were used by the Nochrim for violent purposes. Since it could happen that another Jew might be arrested and become the victim of the corrupt system of justice, or sadistic sports, of the Nochrim in these places, a Jew is not permitted to take part in the building of these structures. (See also Rashi to 15b, DH Shalshela'os.)
The RITVA seems to understand the Mishnah in the same way he explains an earlier Halachah. Earlier, he explains that the reason why a Jew is forbidden from selling deadly weapons to Nochrim is the verse of "Lifnei Iver" -- a Jew who sells such weapons to a Nochri empowers the Nochri to kill (which Nochrim are commanded not to do). The Ritva, in his comments on the Mishnah here, seems to follow his reasoning earlier. He explains that one is prohibited to help a Nochri build such structures because of "Lifnei Iver" -- the Nochrim will use these structures to kill people (as Rashi explains). In contrast to Rashi's explanation, however, the Ritva omits that the injustice might be meted out to Jews, and he writes instead that helping build such structures is prohibited because the Nochrim are suspected of harming people and killing them unjustly.
The RI MI'LUNIL records both the reason of Rashi and the reason of the Ritva. When he records Rashi's reason, he adds that building such structures constitutes a violation of the verse, "Lo Sa'amod Al Dam Re'echa" (Vayikra 19:16), the Torah's commandment to save the life of another Jew. If one is commanded to save the life of a fellow Jew, then certainly one may not cause him to be harmed in any way, direct or indirect.
The SEDER YAKOV infers that the Rambam agrees with the Ri mi'Lunil's explanation. The Rambam records these laws twice (Hilchos Avodah Zarah 9:8, and Hilchos Rotze'ach 12:12). Why does the Rambam need to record these laws twice? Perhaps it is because he maintains that helping a Nochri build such structures is prohibited because of two reasons. In Hilchos Avodah Zarah, the Rambam is discussing the prohibition of "Lifnei Iver." He states that just as one is prohibited from selling to Nochrim objects that will help them enhance their worship of Avodah Zarah, one also is prohibited from selling to them objects that harm the populace. In Hilchos Rotze'ach, he records the law based on the other reason -- that one is prohibited from giving any assistance to Nochrim in a matter that might lead to the harm or death of a Jew. (Y. MONTROSE)

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

2) AGADAH: REBBI ELIEZER WAS "NITFAS L'MINUS"
QUESTION: The Gemara relates that when Rebbi Eliezer was "Nitfas l'Minus," he was brought up to the "Gardom" to be judged. Who arrested him and took him to the Gardom, and for what was he being judged? Moreover, why was he so distressed after his release?
ANSWERS:
(a) RASHI (DH l'Minus) explains that he was arrested by "Minim" who wanted to force him to serve Avodah Zarah. In this context, "Minim" refers to people who are idol-worshippers (see Rashi to Chulin 13b, DH Min). This also seems to be the understanding of the CHIDUSHEI HA'RA'AVAD. The Ra'avad comments that when the judge asked Rebbi Eliezer why such an esteemed elder was "wasting time with these idle matters," he was referring to Rebbi Eliezer's devotion to learning Torah.
The text in some versions of the Tosefta in Chulin (2:6) is vague as to the source of Rebbi Eliezer's distress. The Tosefta says merely that Rebbi Eliezer was pained that he was "Nitfas l'Minus." Similarly, Rashi, as cited by the Ein Yakov here, comments that Rebbi Eliezer wanted to do Teshuvah but did not know why this misfortune happened to him, and thus he was distressed. Apparently, the Tosefta and Rashi mean merely that this was a frightening and difficult experience that could have happened only through Divine retribution of "Midah k'Neged Midah" for some act of Aveirah related to Avodah Zarah that he had done.
The SEDER YAKOV suggests another approach to understanding the Gemara. The judged who freed Rebbi Eliezer first pronounced the name of his god as a way of swearing that he was freeing him. It caused Rebbi Eliezer great pain that he was the cause of an oath taken in the name of an idol, even though he had no way of knowing that such a thing would happen. He was distressed that he had transgressed the verse, "Lo Yishama Al Picha" -- "It should not be heard on your mouth" (Shemos 23:13), a prohibition against even causing someone else (even a Nochri) to mention the name of a false god (see Rashi to 6a, DH Mishum). Rebbi Eliezer tried to recall a sin that he might have done intentionally, which would have caused him to do this sin as well.
(b) The DIKDUKEI SOFRIM questions Rashi's explanation from a chronological perspective: Rebbi Eliezer lived during the time of the second Beis ha'Mikdash. During that time, there was no religious persecution, and the Jews were not forced to serve Avodah Zarah. He explains instead that the "Minus" mentioned here refers to the beginnings of the teachings of the Nazarene. The Romans persecuted anyone they found associated with the Nazarene and anyone whom they believed was connected to the Nazarene in any way. (This explanation also might explain the variant text in the words of Rashi. Instead of saying that Rebbi Eliezer was taken by "Minim," some texts of Rashi read that he was taken by "Minei Romayim," or "Roman heretics.")
This also seems to be the intention of the version of this incident as it appears in one edition of the Tosefta (Tzukermandel edition) in Chulin. According to the text of that edition, Rebbi Eliezer was distressed that he had been "Nitfas Al Divrei Minus" ("apprehended on the matter of words of heresy"), which implies that his captors accused him of thinking or speaking heresy.
This is also the approach of RABEINU CHANANEL, who writes here that Rebbi Eliezer was accused of believing in the existence of two gods. The NETZIV in MEROMEI SADEH writes that the words of Rabeinu Chananel perhaps should read "three" gods, referring to the Nazarene concept of that belief.
What basis, however, was there for the Romans to suspect that Rebbi Eliezer was connected in any way with the Nazarene?
The CHILUFEI GIRSA'OS, NETZIV, and others explain that this is the reason why Rebbi Eliezer was distressed after this event and was inconsolable. He was worried about the statement of the Chachamim (Moed Katan 18b) that a person is not suspected of wrongdoing unless he at least thought about doing that sin. Rebbi Eliezer understood, therefore, that he must have entertained some type of heretical thought. Rebbi Akiva suggested to him the possibility that Rebbi Eliezer perhaps once received some benefit from a heretic. Rebbi Eliezer responded that he now saw the Heavenly retribution in this incident, because he indeed once took pleasure from the comments of a heretic. (Y. MONTROSE)

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