Siman - Pesachim Daf 18

  • A cow drinking mei chatas

Rav Nachman bar Yitzchak brought a Mishnah from Parah to prove that when Rebbe Yehuda retracted his ruling and said mashkin can only be metamei mid’Rabbanon, it was not just with regard to keilim but also to food. The Mishnah stated, פרה ששתתה מי חטאת בשרה טמא – if a cow drank mei chatas its flesh is tamei. Rebbe Yehudah said, בטלו במעיה – the water is nullified in the cow’s intestines and lost its capacity to be metamei, therefore, the flesh, which is considered food, is tahor. Rashi explains that since the water becomes unfit for purification within the cow’s innards, it loses its capacity to be metamei. If Rebbe Yehudah held that mashkin is metamei mid’Oraysa, then the water should be metamei regardless if it is fit for mei chatas.

The Gemara says that this is not a proof that Rebbe Yehuda holds mashkin are only metamei food mid’Rabbanon,  because it may be that בטלו במעיה means that it became nullified from being metamei טומאה חמורה, meaning, that it cannot make a person or vessels tamei, but it still can be metamei טומאה קלה, such as food, and in this case flesh.  Rav Ashi answered, לעולם בטלו במיעה לגמרי – Really Rebbe Yehudah holds that the water is completely nullified in the cow’s intestines, משום דהוה ליה משקה סרוח – because once inside the cow the water is a putrid beverage, which is entirely precluded from tumah.

  • Yitma

Rabbah bar bar Chanah taught that Rebbe Yose, who holds that tamei liquid can be metamei food mid’Oraysa but it is only metamei keilim mid’Rabbanon, based his opinion on his Rebbe, Rebbe Akiva. Rebbe Akiva taught in a Mishnah regarding an earthenware vessel, וכל כלי חרש אשר יפל מהם – Any earthenware vessel that it will fall into it, referring to a dead sheretz, everything in it…of any food item…shall be contaminated. The passuk does not use the word tamei, but yitma, which can be read yitamei, implying it has the capacity to metamei other things as well. When the sheretz enters the air space of an earthenware vessel it makes the kli a rishon, even if it did not touch its walls. Any food that is in the kli or enters it, will then become a sheini. Rebbe Akiva is teaching that this sheini food will make other food, even chullin, a shelishi.

Rebbe Yose uses a similar passuk with the word “yitma” to derive his ruling that mashkin is metamei foods mid’Oraysa.

  • מילתא דאתיא בקל וחומר טרח וכתב לה קרא

The Gemara on Amud Beis brings two pesukim regarding mashkin that became tamei from a sheretz. One passuk deals with mashkin that became tamei from touching a sheretz directly, and the other with mashkin that entered a kli that was tamei from a sheretz. The din for both is that the mashkin cannot be metamei another beverage. The Gemara asks that the Torah could have just taught the passuk regarding the mashkin that touched the sheretz directly, that it is not metamei other mashkin, and kal v’chomer we would know that mashkin that touched the kli that was tamei from the sheretz cannot be metamei another mashkin. The Gemara answers, מילתא דאתיא בקל וחומר טרח וכתב לה קרא – Something that could have been derived though a kal v’chomer, the Torah sometimes take the trouble to write explicitly.