Clarification: This implies that it is specifically the Basar that is Tamei, but not Adam and Keilim, because it is Pasul due to Hesech ha'Da'as.

Question: Since the Tum'ah Chamurah has departed (the Mei Chatas), Tum'ah Kalah should not apply either ...

Question (cont.): Like we say in Perek Ba Si'man(Nidah 51.) and in Perek T'vul-Yom (Zevachim 105.) 'Whatever will eventually be Metamei Tum'ah Chamurah does not require a Hechsher Sheretz, but is considered as if it touched a Sheretz'.

(cont.): And that refers specifically to where it stands to be Metamei Tum'ah Chamurah, but where it is no longer fit to be Metamei Tum'ah Chamurah, it requires Hechsher?

Proof: As we say in Perek Beheimah ha'Makshah (Chulin 73:) with regard to'Basar that became detached from Eiver min ha'Chai, where the fact that it was Metamei Tum'ah Chamurah when it was still attached to its source does not help to render it Muchshar, since once it separated, it no longer is?

Answer: The case there is different, since its initial use was (not as a food, but) as if it was a piece of wood, like the Gemara explains in 'ha'Or ve'ha'Rotav' (Ibid.129.) See also Maharam.

Answer (cont.): Hence, once it separates from its source, it requires Hechsher.

Answer (cont.): Whereas Mei Chatas initially needs to be fit to drink, in which case its Tum'ah Chamurah is not merely like a piece of wood, but because it was actually fit for a person to drink.

Answer (cont.): Consequently, even though it becomes Pasul, its Tum'as Mashkin has not gone away.

Clarification: But as long as it is in its mouth, the water is not Bateil.

Implied Question: Even though we say in Maseches Parah (9:3) that 'All birds invalidate the Mei Chatas'.

Answer: The Ri explains that it speaks there before the Kidush, and it becomes Pasul because, as Rashi explains in 'ha'Megaresh (Gitin 86. [See Hagahos ve'Tziyunim]) - either because it needs initially to be placed in a K'li or because work was done with it.

Answer (cont.): Whereas her it speaks after the Kidush, since it considers them subject to Tum'ah Chamurah, and work does not disqualify it after the Kidush.

Proof: As we learned in Maseches Parah (4:4) 'Work renders the Mei Chatas Pasul, until the ashes have been added.

Source: The Sifri learns this from the fact that the Torah writes "le'Mei Nidah" - which it already is.

Conclusion: And the reason that it becomes Bateil in the cow's stomach is because of Hesech ha'Da'as.

Alernative Reason: The Tosefta in Mikva'os (Perek 8) ascribes Rebbi Yehudah's ruling to the Pasuk "le'Mishmeres" - to preclude this water, which is no longer subject to "le'Mishmeres", since a cow drank from it

Explanation #1: Rashi cites the source as the D'rashah later (on Amud Beis) "Yitma", 'that something that is Tamei cannot render Tamei its own equivalent'.

Alternative Text: Some texts do not read 'later'.

Proof: Indeed, the words 'We do not find' imply that we learn it from an external source, and not from the implication of the word "Yitma".

Explanation #2: And the Ri gives the source for 'We do not find ... ' is based on the D'rashah that we learned above (on Daf 14.) from "Tamei Hu".

Clarification: Because if one would think that the Pasuk comes for Tum'as Mashkin, the Torah ought to insert just one "Yitma". Why does insert two? To preclude something that is Tamei from rendering Tamei its own equivalent'.

Question: By the same token, liquid that became Tamei via food ought not to be Metamei food; and food that became Tamei via liquid ought not to be Metamei liquid?

Answer: Because here the Kal va'Chomer is justified, since the reason that a K'li is not Metamei a K'li, is because it is not an Av ha'Tum'ah, and its Tum'ah is therefore less severe; indeed if it was an Av haTum'ah, it would be Metamei a K'li.

Answer (cont.): Whereas the fact that a food is not Metamei a food is due to the principle that it cannot render Tamei its own equivalent.

Question: From where do we know that liquid that became Tamei via a K'li that touched a Meis does not render another K'li Tamei ...

Question (cont.): We cannot learn it from the Kal va'Chomer from K'li, seeing as a K'li that touched a Meis is Metamei a K'li.

Answer: The current Pasuk is talking about a Sheretz, and does not incorporate liquid that touched a K'li that in turn, touched a Meis.

Question: Letus learn from a Kal va'Chomer from food - If food, which became Tamei via a Sheretz is Metamei liquid, a Sheretz itself should certainly do so!

Question (cont.): And then we will say that both liquid and food will be Metamei a K'li?

Answer: Food cannot be Metamei a K'li, even if it it became Tamei via a Sheretz ...

Answer (cont.): From a Kal va'Chomer from liquid that became Tamei via a K'li, which is Metami food but not a K'li; food which became Tamei via a Sheretz, which is not Metamei food (from the Pasuk "Hu Tamei") will certainly not be Metamei a K'li!

Question: Rebbi Ya'akov from Orleans asks that, if so, liquid that became Tamei via a Sheretz ought to be a Sheini, like liquid that became Tamei via a K'li; Let the Kal va'Chomer render it Tamei, and from 'Dayo' we will learn that it only becomes a Sheini?

Source #1: Like we find in 'Keitzad ha'Regel (Bava Kama 25:) regarding to a mat by a Meis, where the Gemara says 'Let the Kal va'Chomer take effect with regard to Tum'as Erev, and from 'Dayo' we will learn that it is not Tamei for seven days'?

Source #2: And in the same way, the Gemara says regarding to Keren in the courtyard of the Nizak, 'Let the Kal va'Chomer take effect with regard to paying Nezek Shaleim, and from 'Dayo' we will learn that the payment must come out of the body of the Mazik (ox)?

Answer: This is not a Kashya, says the Ri. One cannot make such a distinction here, he explains, seeing as we do not find anything that touches a Sheretz that does not become a Rishon.

Answer (cont.): Whereas by a Meis, there are things that touch it that become a Rishon (and not an Av), such as food and earthenware vessels.

Answer (cont.): And (regarding the second source) Nezek Shaleim and paying from the body are two separate issues (which do not clash, unlike a Rishon and a Sheini, which do).

Refuted Answer: One cannot however answer by learning the Kal va'Chomer like this 'And if Adam and Keilim, which do not become Tamei via the air of an earthenware vessel do become Tamei via a Sheretz, liquid, which does become Tamei via the air of an earthenware vessel should certainly become Tamei via a Sheretz ...

Refutation: Since there too, one can say 'Dayo', as is evident in 'Keitzad ha'Regel (Ibid.).

Alternative Explanation: It would be possible to learn that food is not Metamei a K'li from a Kal va'Chomer - 'If a K'li that is Metamei food is not Metamei a K'li, food which is Metamei food should certainly be Metamei a K'li.

Question: The Ri asks that this is not a good Kal va'Chomer - seeing as this susceptibility to Tum'ah is not effective with regard to receiving Tum'ah from liquids, whereas food does - a proof that food is more stringent after all?

Refuted Explanation: And earlier in the Sugya, when we learned that a liquid is not Metamei a K'li, we cannot learn from a food which is Metamei a liquid, yet it is not Metamei a K'li, how much more so a liquid which is not Metamei another liquid.

Refutation #1: Since from where do we know that food is not Metamei a K'li?

Refutation #2: Moreover, liquid is more stringent than food, seeing as it is Metamei food?

Refuted Explanation: And here, we cannot learn a Kal va'Chomer likewe did earlier that 'If a K'li which is Metamei food is not Metamei a K'li, how much more so food which becomes Tamei via a K'li!

Refutation: Because in any cacse, from where will we know food that becomes Tamei via a Sheretz?

Observation: Even the opinion that holds 'Dayo' even if is means negating the Kal va'Chomer, will concede here that we will learn a Shelishi from a Mechusar Kipurim with a Mah Matzinu.

. Observation (cont.): Since a Mechusar Kipurim is like a Shelishi - since he does not affect T'rumah at all, and only renders Kodesh, Pasul, and the same will apply to all cases of Shelishi.

Conclusion: That explains why the Kal va'Chomer here is more powerful than usual, and one cannot apply 'Dayo', and say that just as there a 'Shelishi and no more, also here, a Shelishi and no more!')

Explanation #1: The Gemara prefers to cite a Pasuk.

Explanation #1 (cont.): Although it could have learned a Shelishi la'Kodesh via a Kal va'Chomer from a T'vul-Yom.

Explanation #2: Rashi however, explains that it had to learn a Shelishi from a Pasuk, in order to avoid having to say 'Dayo'.

Conclusion: But now that we learn Shelishi from the Torah, we can no longer apply 'Dayo', seeing as the Kal va'Chomer would then be negated.