1) A WOMAN'S EXEMPTION FROM THE OBLIGATION TO CIRCUMCISE HER SON
QUESTION: The Gemara cites a verse to teach that a woman is not obligated to circumcise her son.
However, the Mishnah teaches that a woman is exempt from all Mitzvos Aseh sheha'Zeman Gerama. The Gemara in Eruvin (96a) teaches that the Mitzvah of Tefilin is considered a Mitzvas Aseh sheha'Zeman Gerama according to the opinion that the Tefilin are worn only during the day and not at night. Since the Mitzvah of Milah must be performed during the day and not at night, why is a verse needed to teach that a woman is not obligated to circumcise her son? Milah is a Mitzvas Aseh sheha'Zeman Gerama from which women are exempt! (TOSFOS DH Oso)
ANSWERS:
(a) TOSFOS (here and in Yevamos 72b) answers that the Gemara here follows the opinion of Rebbi Elazar b'Rebbi Shimon (Yevamos 72b) who maintains that Milah may be performed at night when it is performed after the eighth day ("Milah she'Lo bi'Zemano"), and thus Milah is not a Mitzvas Aseh sheha'Zeman Gerama. When the Gemara asks for a source that a woman is not obligated to circumcise her son, it knows that a woman is not obligated to circumcise her son on the eighth day (when the Mitzvah of Milah is a Mitzvas Aseh sheha'Zeman Gerama since it may not be performed at night). The Gemara asks that perhaps she is obligated to circumcise her son after the eighth day (when the Mitzvah of Milah may be performed at night, according to Rebbi Elazar b'Rebbi Shimon). (See Tosfos to Megilah 20a, DH d'Chesiv.)
(b) TOSFOS in Megilah (20a) suggests another answer. The Gemara initially assumes that a woman is obligated to perform a Mitzvas Aseh which carries the punishment of Kares, even if it is a Mitzvas Aseh sheha'Zeman Gerama. (Although the punishment of Kares applies only to the son who is left uncircumcised and not to the mother, it nevertheless gives the Mitzvah of Milah such significance that the mother may be obligated to ensure that her son is circumcised.)
(c) The RITVA answers that when the father does not circumcise his son, the responsibility to circumcise the son rests on Beis Din (as the Gemara here says). This means that every member of the Jewish people is responsible to ensure that the son is circumcised. The Gemara initially assumed that the mother has the same obligation as every other member of the Jewish people and she must ensure that the child becomes circumcised. This obligation requires that she circumcise the child for the benefit of the child and not because she has a personal Mitzvah to circumcise her son. The verse therefore teaches that she has no obligation to circumcise the child.
(d) The TOSFOS RID explains that the Mitzvah of Milah does not obligate the parent to perform the specific act of excising the son's Orlah, but rather it obligates the parent to ensure that the son becomes circumcised. The parent fulfills this Mitzvah by appointing a Mohel and making the other preparations for the Milah. Accordingly, the parent's Mitzvah applies both during the day and at night (even though the actual circumcision must be done during the day) and it is not a Mitzvas Aseh sheha'Zeman Gerama.
The SHACH (CM 382:4) infers from the ROSH and RAMBAM that if the father knows how to perform the act of Milah, he is obligated to perform the circumcision himself. This is also the opinion of the OR ZARU'A (cited by the DARCHEI MOSHE YD 264:1).
The DARCHEI MOSHE and TEVU'OS SHOR (cited by the KETZOS HA'CHOSHEN CM 382:2) disagree with the Shach. They write that according to the opinion of the Tosfos Rid, it is clear that there is no Mitzvah for the father to perform the actual circumcision but rather to ensure that the son becomes circumcised.

29b----------------------------------------29b

2) AGADAH: THE POWER OF THE SERPENT
QUESTION: The Gemara relates that a certain demon resided in the study hall of Abaye. When Abaye heard that the great Rav Acha bar Yakov was coming to study in his Yeshiva, he gave instructions that no one offer Rav Acha a place to sleep. Rav Acha would have no choice but to sleep in the study hall, and in his merit the demon would be destroyed. When Rav Acha arrived, no one offered him a place to sleep, and so he went to sleep in the study hall. The demon appeared to him in the form of a seven-headed serpent. Rav Acha began to pray, and each time he prostrated himself one of the serpent's heads fell off.
How did Rav Acha bar Yakov's prayers vanquish the serpent? Why did one of the serpent's heads fall off each time Rav Acha prostrated himself?
ANSWER: The MAHARSHA cites the Gemara in Bava Kama (16a) which teaches that if a person, during his lifetime, does not bow down at the blessing of "Modim" in the Shemoneh Esreh, after seven years in the grave his spine turns into a serpent (Nachash). TOSFOS there (16b, DH v'Hu) explains the intent of that Gemara based on the Gemara in Berachos (12a) which teaches that when a person bows at "Modim" he should "straighten himself like a snake" (and bring his head up first). Hence, one who does not bow during "Modim" is punished measure-for-measure, and his spine becomes a snake.
Accordingly, bowing at "Modim" is an effective way to vanquish the powers of the serpent, and thus by bowing down Rav Acha bar Yakov was able to humble the serpent.
The Maharsha adds that the seven heads of the serpent correspond to the seven powers of Tum'ah which the primeval snake brought into the world (and the seven curses given to Adam ha'Rishon, and the seven years after which the spine turns into a snake).
The SEFER HA'MIKNAH adds that this approach explains why Yakov Avinu prostrated himself seven times before Esav when Esav approached him (Bereishis 33:3). Esav's ministering angel is identified with the primeval serpent (Midrash Rabah, end of Devarim) which has seven qualities (or powers, "Kochos") of Tum'ah. By bowing down seven times, Yakov Avinu was able to weaken the seven powers of the serpent and thereby peacefully co-exist with Esav.
The Sefer ha'Miknah points out that the Gematriya of the name "Yakov" (182) equals seven times the Gematriya of the Holy Name of Hash-m (26 X 7). When Yitzchak gave seven blessings to Yakov, he endowed Yakov with seven powers of Kedushah, holiness, as represented by his name.
The name "Yitzchak" (208) is equal to eight times the Holy Name of Hash-m (26 X 8). When Esav cried out to his father, "Have you not one blessing left for me," he begged for the eighth power of holiness from his father. It is this power of Kedushah that Yitzchak gave to Esav which keeps Esav and his descendants alive. This is alluded to in Esav's name, the Gematriya of which (376) equals seven times the word "Tamei" (50 X 7), representing the seven powers of Tum'ah, plus another 26 representing the Kedushah of the Name of Hash-m. When Yakov Avinu bowed down seven times, his humility (which was directed towards Hash-m and which is alluded to in his name, "Yakov" -- "Ekev Anavah Yir'as Hash-m," Mishlei 22:4) removed the powers of Tum'ah from Esav so that only the power of Kedushah remained, and they were able to live like brothers. (This is implied by the verse (Bereishis 33:3) which says that Yakov's prostrations led to the effect of "Ad Gishto Ad Achiv").
This may be the intention of the Midrash there which states that Esav tried to bite Yakov's neck but his neck hardened like stone and, as a result, Esav's teeth broke, as the verse says, "Shinei Resha'im Shibarta" -- "You broke the teeth of the wicked" (Tehilim 3:8). The Midrash means that Yakov, by humbling himself to Hash-m, was able to remove Esav's "tooth," or "Shen" (the Gematriya of which is 350, which represents the seven powers of Tum'ah as mentioned above). This is also the intention of the Hagadah Shel Pesach which states that one should respond to the wicked son by "weakening his teeth" ("Hakheh Es Shinav").
The letters of the word "Shen" -- "Shin" and "Nun" -- surround the letter "Ches" in "Nachash" (Nun-Ches-Shin) and surround the letter "Tes" in "Satan" (Sin-Tes-Nun). When those two surrounded letters are combined, they spell "Chet" (sin). The VILNA GA'ON (Kol Eliyahu #235) explains this phenomenon based on the words of the Gemara in Sanhedrin (78a), "The poison of the serpent stands between his teeth (Bein Shinav)." The letters of the word "Shen" (which represents the powers of Tum'ah, as mentioned above) enclose the "Ches" and "Tes" (which spell "Chet") in the words "Nachash" and "Satan." "Chet" is the true "poison" of the serpent which brings death to the world (see Rosh Hashanah 29a and Berachos 33a).
In the same vein, the incident of Rav Acha bar Yakov and the serpent may be understood in a metaphorical sense. A certain "enlightened" individual who denied the existence of Hash-m and His Torah was accustomed to entering the Beis Midrash at night when Abaye was not there. He would attempt to weaken the faith of the students with his heretical arguments and to dissuade them from the study of Torah and enjoin them to study instead the "seven wisdoms" of the physical world, which he considered superior to all other forms of study.
When he engaged Rav Acha bar Yakov in a discussion, the Tzadik was able to point out to him the flaws of all of the worldly wisdoms. Through his Yir'as Shamayim and pure faith which derived from his humility before his Creator, Rav Acha bar Yakov forced the "serpent" to succumb so that he never returned to harass the students again. (M. KORNFELD)

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