QUESTION: The Gemara quotes a Beraisa that teaches that if a loaf of bread of Terumah was left on a shelf above an object that was Tamei, and the loaf was found later on the floor next to the object, we do not assume that the loaf fell on the object and rolled to the side. Even if the loaf of bread had been situated on the shelf in such a way that it would have had to touch the Tamei object it if fell from the shelf to the floor, the loaf is deemed Tahor, because we assume that a Tahor person came and placed the load on the floor.

However, we find the opposite ruling in Chulin (9b). The Gemara there discusses a vessel filled with water that was designated to be used for Mei Chatas (the water used in the sprinkling of the ashes of the Parah Adumah). The vessel was left uncovered, and then it was found to be covered. The water inside the vessel is deemed Tamei and may no longer be used as Mei Chatas, because we assume that a Tamei person placed the cover on the vessel, rendering its contents Tamei.

Why does the Gemara there assume that a Tamei person covered the vessel, while the Gemara here assumes that a Tahor person moved the bread?

(a) TOSFOS here and in Chulin (9b, DH she'Ani Omer) explains that in the case of the loaf of bread, the reason why we assume that a Tahor person moved the bread is because the bread was in a precarious position in which it was at risk of becoming Tamei (since it was directly above an object that was Tamei). We may assume that the motive for moving it was to prevent it from becoming Tamei, and, obviously, since it was moved in order to prevent it from becoming Tamei, it must have been a person who was Tahor who moved it. In contrast, the open vessel of water was not at risk of becoming Tamei, and since there was no motive for moving it have no motive for moving it, we assume that it was moved by a person who was Tamei.

(b) Tosfos quotes RABEINU TAM who explains that in the case of the Gemara here, only food is involved, and thus, out of doubt, the food is considered to be Tahor (unless it is in Reshus ha'Yachid). The case of the Gemara in Chulin involves a vessel. The Chachamim decreed that when the doubt involves a vessel, the vessel is considered Tamei (see Taharos 4:5).

What is the reason for this difference between food and a vessel?

1. Tosfos explains that since vessels can be purified by being immersed in a Mikvah, the Chachamim were stringent in cases involving vessels, since there is a way to make them Tahor. Food, in contrast, cannot be immersed in a Mikvah, and thus the Chachamim were not stringent with regard to food.

The RAMBAN questions Rabeinu Tam's reasoning. There are some types of vessels which, like food, cannot become Tahor by being immersed in a Mikvah, such as earthenware vessels (Klei Cheres). Why, then, are such vessels considered Tamei when there is a doubt about who placed the cover on them?

The RAN answers the Ramban's question on Rabeinu Tam's understanding of the difference between vessels and food. Although earthenware vessels indeed would be irrevocably ruined if the Chachamim decreed them to be Tamei, nevertheless the Chachamim did not want to make an exception to their decree ("Lo Plug"), and therefore they included all vessels in their decree (see also MAHARAM).

2. The Ramban therefore gives a different explanation for the difference between vessels and food. He explains that a person is not particular about where he leaves a vessel, while a person is particular where he leaves food. A person will place food only in a place where it will not get dirty or ruined. Since vessels are usually handled in any manner, the Chachamim decreed that, in a situation of doubt, any vessel is Tamei, even if it is a vessel that is carefully handled and kept only in the house. In contrast, food is always handled carefully and only by people who are Tahor, and, therefore, in a situation of doubt, we assume that food was handled by a Tahor person. (The Ramban adds that the decree of Tum'ah was not applied to fruit that falls in the middle of the street, because no one eats such fruit anyway.)

3. The RAMBAM (Hilchos Mishkav u'Moshav 12:16) explains that it is logical to assume that a food was moved by a trusted person (a Chaver, who is Tahor), because if a person who was not trustworthy moved the food, then he would have eaten it instead of replacing it! Since the person who moved the food is trustworthy, we may assume that he was Tahor as well. Kelim, on the other hand, might have been moved by an unscrupulous person, who "borrowed" the object without permission, used it, and returned it. Such a person who borrows an object without the owner's permission is considered by the Chachamim to be a thief (Bava Metzia 41a), and thus we may assume that this thief did not heed the laws of Tum'ah and Taharah just as he did not heed the laws of property rights. (See also Insights to Chulin 9:4.)

QUESTION: The Gemara discusses the opinion of the Rabanan, who maintain that the status of the Taharos handled by a woman who saw Dam Nidah is judged in one of two ways. If her last clean Bedikah was within twenty-four hours, then only the Taharos she handled after that Bedikah are deemed Tamei. If her last clean Bedikah was not within the last twenty-four hours, then the Taharos she handled within the last twenty-four hours are Tamei.

Rabah asked, what is the reasoning of the Rabanan? It must be that they maintain that a woman realizes when she becomes Tamei, and we do not assume she became Tamei before she found the Dam. Abaye asked Rabah that if that is the reasoning of the Rabanan, then why do the Rabanan say that the Taharos she handled are Tamei? They should rule like Shamai, who says that the Taharos that she handled are never deemed Tamei, because a woman knows when she becomes Tamei!

The Gemara explains that Rabah knew that his answer was inaccurate, and that he said it merely in order to sharpen Abaye's thinking. Rabah wanted to make sure that Abaye would not accept such a faulty statement (even though it was said by his Rebbi).

The RASHBA asks that there seems to be a basis for Rabah's original answer. Perhaps the Rabanan agree with Shamai in principle, but they maintain that there must be a Seyag (fence) to this Halachah, in case the blood was gathered in the Bayis ha'Chitzon for some time before the woman saw it (see RASHI to 2a, DH Shamai). Although the Rabanan do not agree with Hillel to suspect that this occurred after the last Bedikah, it is possible that they agree that this possibility is strong enough grounds to establish a Chumra (stringency) to take into account the possibility that this might have occurred within the last twenty-four hours.

If there is a basis for Rabah's answer, then why does the Gemara say that his answer was intended merely to test Abaye?

(a) It seems that RASHI (DH Mai Taima) was bothered by this question. Rashi explains that Rabah's answer was addressing the following question: the opinion of Hillel is understandable -- he suspects that a woman saw blood immediately after her last clean Bedikah, and thus there is a concern that all Taharos that she handled after that Bedikah are Tamei. What, though, is the reason to say that any Taharos that she handled within the past twenty-four hours are Tamei? From where does this twenty-four hour time span come? If we suspect in any way that she became Tamei without her knowledge, then there is no reason to suspect that her Tamei started arbitrarily twenty-four hours before she noticed it!

This answer is stated more explicitly by both the RASHBA and the RITVA.

(b) The MEI NIDAH gives a different approach. He quotes TOSFOS (3a, DH v'Iba'is Eima) who explains that the reasoning of Shamai -- that a woman knows when she sees blood -- has an additional reason behind it: a woman is considered Tahor until proven to be Tamei (Chezkas Taharah). Had Rabah said that the reasoning of the Rabanan is that a woman is considered Tahor until proven otherwise, we would understand why the Rabanan would make an added stringency of twenty-four hours -- it is because we would be relying only on a Chazakah, and not on any clear knowledge. However, Rabah did not say this, but instead he said that the Rabanan's reason is that a woman always knows when she sees blood. Abaye said that this is not a valid reason for the Rabanan to enact a stringency of twenty-four hours., because if she knows for certain that she did not see blood, we should say that there is no reason at all for a stringency of twenty-fours. (Y. MONTROSE)