Our Gemara on this daf continues discussing a dispute between Rabbi Yehuda and the Tanna Kama regarding whether the prohibition of Gid Hanashe applies to a fetus.
It is brought down from the Chozeh MiLublin (Chanukas HaTorah Hachadash, Vayishlach) that according to the Zohar (Bereishis 170b) each limb of a person corresponds to an angel, and the Gid Hanashe corresponds to the angel in charge of the evil inclination. Sanhedrin (92b) reports the following dispute between Rabbi Yehuda HaNasi and Antoninus:
“Antoninos said to Rabbi Yehuda HaNasi: From when does the evil inclination dominate a person? Is it from the moment of the formation of the embryo or from the moment of emergence from the womb? Rabbi Yehuda HaNasi said to him: It is from the moment of the formation of the embryo. Antoninos said to him: If so, the evil inclination would cause the fetus to kick his mother’s innards and emerge from the womb. Rather, the evil inclination dominates a person from the moment of emergence from the womb. Rabbi Yehuda HaNasi said: Antoninos taught me this matter, and there is a verse that supports him, as it is stated: ‘Sin crouches at the entrance’ (Genesis 4:7), indicating that it is from the moment of birth, when the newborn emerges from the entrance of his mother’s womb, that the evil inclination lurks.”
In the end, Rabbi Yehuda HaNasi conceded to Antoninus. This is why Rabbi Yehuda HaNasi holds that there is no prohibition of Gid Hanashe on a fetus, because it does not yet have an evil inclination, and therefore not yet the problematic Gid Hanashe.
Returning to this Zohar, it states that just as there is an angel that corresponds to each limb, there is each day of the solar year that corresponds with the 365 prohibitions in the Torah and 365 sinews in the body. The day of Tisha B’Av corresponds to the Gid Hanashe, just as the evil inclination is the angel that corresponds with that part of the body. The Shach on the Torah (ibid 32:33) says one who eats Gid Hanashe is as if he ate on Tisha B’Av, and the prohibition against eating both left and right sides corresponds to the two Batei Mikdash that were destroyed.
Everything in the physical world is subject to vulnerabilities. Fire, though powerful, can be extinguished by water. Iron can melt. The most mighty animal still can be brought down by poison. We also have spiritual vulnerabilities. Yaakov wrestles with an angel and wins, but does not come out unscathed. What is our psychological vulnerability? The yetzer hara. Tisha B’Av and other catastrophes were military defeats, but their ultimate cause was a spiritual demise. As it says in Eicha Rabbah (1:41): “Had war not been waged against me from on high, could you have waged war against me? Had fire not been sent against me from on high, could you have overcome me? Rather, you killed a dead lion. You ground already ground flour. You set fire to a burned city.”
The moral collapse of society led to physical vulnerability. As Yeshaiyahu (1:23) laments: “Your rulers are rebellious, and befriend thieves. They lust after bribes and quest for indulgences. They do not judge the plight of the orphan, and the widow’s cause never reaches them.”
It is interesting that this forbidden part of the animal is inedible and tasteless (Chulin 99b). The message may be that the immoral things we desire which lead us astray are illusory and ultimately tasteless.
Gid Hanashe is the only prohibition mentioned before the giving of the Torah and not reiterated at Har Sinai (Sanhedrin 59a). Why? Some “mitzvos” are so fundamental that they are not mitzvos, because they are prerequisites. For example, according to the Bahag, there is no mitzvah to believe in God, because belief in God is the necessary condition to have a mitzvah. It is BEFORE the mitzvos (see Hasagos HaRamban Sefer Hamitzvos, Aseh 1). So too, Gid Hanashe, which represents managing the yetzer hara, can be seen as a pre-condition for all the mitzvos. This “first mitzvah” is fundamental, and it reminds us that our downfall is never the enemies from without, but rather from within.