1) PREVENTING THE WOMAN FROM DISEMPOWERING THE "MEI SOTAH"
QUESTION: The Mishnah teaches that the woman must wave ("Tenufah") the vessel which contains her Minchah offering. If the woman is required to hold the vessel which contains her Minchah offering, there seems to be a simple way for a cunning woman to prevent the Mei Sotah from effectively testing her and proving her guilt. She can simply make herself Tamei to a Mes when no one is watching, and when she holds the vessel which contains the Minchah, she will be Metamei the vessel which will then be Metamei the Minchah. Since the Minchah is Pasul, the Mei Sotah will not be effective to prove her guilt. (HAFLA'AH, cited by the CHASAM SOFER, end of Parshas Naso)
(a) The HAFLA'AH answers that the Sotah's Korban Minchah is one of the only Minchah offerings not brought with oil. No food item can become Tamei until it has become "Huchshar" through contact with one of the seven qualifying liquids, which include water and oil. The Korban of the Sotah is thus prepared in a such way -- without oil -- that it does not become "Huchshar" so that the woman cannot make it Tamei.
(b) The CHASAM SOFER points out that even if the Minchah was "Huchshar" and did become Tamei, it is still effective in proving the woman's guilt. The Tzitz which the Kohen Gadol wears is "Meratzeh" for the Tum'ah and thus the Minchah offering remains valid.
2) WHEN DOES THE SOTAH DRINK THE "MEI SOTAH"
QUESTIONS: Three different verses in the Torah discuss the procedure of giving the Mei Sotah to the woman to drink. The first verse is "v'Hishkah Es ha'Ishah" (Bamidbar 5:24), written immediately before the verse (5:25) which commands the Kohen to offer the woman's Minchah offering (Hakravas ha'Minchah). The second and third verses are "v'Achar Yashkeh" (5:26) and "v'Hishkah Es ha'Mayim" (5:27), written after the verse of the Hakravas ha'Minchah.
The Tana'im disagree about how to interpret these verses. RASHI explains that Rebbi Akiva and Rebbi Shimon agree that the woman is given the Mei Sotah to drink after the Hakravas ha'Minchah. They disagree about whether the woman is forced to drink in a case in which the Megilas Sotah was erased prematurely (before the Hakravas ha'Minchah) and the woman refuses to drink the Mei Sotah but does not admit guilt.
Rebbi Shimon derives from the verse, "v'Achar Yashkeh" (5:26), that the woman must drink the Mei Sotah after the Hakravas ha'Minchah, and that the woman drinks only after the writing on the Megilas Sotah is entirely erased in the water (i.e. no impression remains; it is not "Rishumo Nikar"). The third verse, "v'Hishkah" (5:27), teaches that she is forced to drink if she refuses to do so. (The first verse, "v'Hishkah" (5:24), which is written before the Hakravas ha'Minchah, teaches that b'Di'eved if she drinks the Mei Sotah before the Minchah is offered, the Mei Sotah is still effective.)
Rebbi Akiva, on the other hand, derives from "v'Achar Yashkeh" (5:26) only that the writing must be entirely erased. He learns from the third verse, "v'Hishkah" (5:27), that the woman drinks the Mei Sotah only after the Minchah is offered. The first "v'Hishkah" (5:24), written before the Hakravas ha'Minchah, teaches that if the Megilah was mistakenly erased before the Hakravas ha'Minchah, the Mei Sotah is still given to the woman to drink.
(a) Rebbi Shimon derives from "v'Achar Yashkeh" both that the woman must drink the Mei Sotah after the Minchah is offered and she must drink after the Megilas Sotah is entirely erased. Why does Rebbi Akiva need two verses to teach these two Halachos if both can be derived from one verse? (RASHASH)
(b) The Mishnah earlier (17b) states that a fully erasable ink must be used for the writing of the Megilas Sotah because the verse says "u'Machah" (Bamidbar 5:23), which teaches that the ink must be completely erased and leave no impression. Since the word "u'Machah" itself teaches that the ink must be entirely erased, why is the second verse of "v'Achar Yashkeh" required to teach that the ink must be entirely erased? (TOSFOS 19a, DH v'Achar)
(a) The RASHASH explains that Rebbi Shimon and Rebbi Akiva disagree about whether "v'Achar Yashkeh" means that the Hashka'ah must be done after everything mentioned in the previous verses is complete, or after only one of the things mentioned in the previous verses is complete. Rebbi Shimon maintains that "v'Achar Yashkeh" means that the Hashka'ah must be done after everything else has been done, and thus he cites this verse as the source for both the Halachah that the Hashka'ah must be done after the Minchah, and the Halachah that it must be done after the complete Mechikah. Rebbi Akiva, on the other hand, maintains that "v'Achar Yashkeh" refers to only one of the previously-mentioned actions, and it teaches that the Hashka'ah must be done only after the Mechikah. Therefore, Rebbi Akiva needs another verse to teach that the Hashka'ah also must wait until the Minchah is offered.
(It is not clear why the Gemara views the Halachah that the writing must be totally erased and not "Rishumo Nikar" as a matter of precedence (what must be done first). It seems that this Halachah is a matter of defining the word "u'Machah" -- "erase"; it is not a question of whether the drinking is done before or after the erasure. The drinking obviously must be done after the Megilas Sotah is erased, as the Gemara here mentions. Perhaps the answer to this question is that when ink is partially erased in water, the remaining impression eventually fades completely after some time passes. However, it fades completely only after the woman has consumed the water. The verse "v'Achar Yashkeh" teaches that the water must completely erase the writing on the Megilas Sotah before she drinks it.)
(b) The TOSFOS SHANTZ explains that the Mishnah derives from "u'Machah" that the ink must be fit to be erased in such a way that no impression remains, and thus ink of "Kankantum" (which is indelible) may not be used. However, one might have thought that as long as the ink is fit to be erased, it does not need to be entirely erased in practice. (The Tosfos Shantz may be referring to the principle of "Kol ha'Ra'uy l'Bilah Ein Bilah Me'akeves Bo" when he suggests that the ink does not need to be entirely erased as long as it is fit to be erased. Alternatively, he may mean that since the ink will fade by itself after it is partially erased, its fading will be considered a fulfillment of "u'Machah.") Therefore, another verse is necessary to teach that the ink must be erased entirely and it does not suffice that it is merely fit to be erased.