Tractate Terumos, Chapter 8, Mishnah 8. To understand this Mishnah we must first present a fundamental dispute between Rabbi Eliezer and Rabbi Yehoshua: is there an obligation to guard Terumah of doubtful status - what the Bartenura calls "terumah teluyah" (suspended Terumah) - from becoming tamei?
The Obligation to Guard - "Mishmeres Terumosai":
We have already noted several times the wording of the verse: "Nasati lecha es mishmeres terumosai" - I have given you the guarding of My Terumos, which establishes an obligation to guard Terumah from tumah. The word "terumosai," as it is pronounced, is plural, and from here we learn that there are two categories of Terumah that require guarding from tumah. This is how Rabbi Eliezer understands it, and in his view the two categories are:
Ordinary tahor Terumah.
Terumah of doubtful status - "terumah teluyah," Terumah about which it is not known whether it became tamei or remained tahor. This is a separate category in its own right, and it too is covered by a distinct Torah command to guard it from tumah.
Rabbi Yehoshua disagrees and holds that only one category of Terumah must be guarded in taharah - ordinary tahor Terumah - while Terumah of doubtful status carries no obligation to guard it. More than that: keeping the doubtful Terumah in the owner's possession in order to prevent it from contracting further tumah, if it ever became tamei to begin with, creates a potential problem. After all, the Terumah remains in his domain, and sooner or later a person is liable to eat from it by mistake, and since this is Terumah that may be tamei, eating it may well be forbidden. Rabbi Yehoshua therefore holds that we have no interest in leaving possibly tamei Terumah sitting with us, and whoever disposes of it sooner is to be praised. For that reason he will take an approach in the Mishnah that hastens its becoming definitely forbidden, in a way that will allow it to be removed.
The Basis of the Dispute: "Yesh eim la'mikra" or "Yesh eim la'masores":
Rabbi Eliezer held that "terumosai" refers to two categories of Terumah. According to the Bartenura, however, Rabbi Yehoshua follows the principle of "yesh eim la'masores" - the received spelling is primary. This dispute runs between the Tannaim throughout every area of derashos: does a derashah rest primarily on the way a word is pronounced or on the way it is written in the Torah? The word "eim" means the essential or primary reading, and "yesh eim la'masores" means that the masores is primary - the way the words are actually written, the precise letters found in the Torah scroll. This is Rabbi Yehoshua's approach. Rabbi Eliezer, by contrast, holds "yesh eim la'mikra" - derashos come primarily from the pronunciation, and "terumosai" is pronounced in the plural: two categories of Terumah.
When we examine the verse itself (Bamidbar 18:8), we find that the second vav, the one that turns the word into "terumosai" rather than "terumasi," is not written there. According to the spelling, one should read "terumasi" in the singular - My Terumah that requires guarding. For this reason Rabbi Yehoshua, who holds "yesh eim la'masores," maintains that there is only one category of Terumah, while Rabbi Eliezer, who holds "yesh eim la'mikra," derives two categories of Terumah from the pronunciation. This is the central point of the Mishnah.
How the Doubt Arises:
A second point, secondary but essential for understanding the Mishnah, is how a doubt comes to be raised regarding two vessels of Terumah. The Mishnah uses the word "chavis," which is usually translated as a barrel of Terumah wine (the precise term is closer to an amphora, but we will follow the accepted and familiar translation). We are speaking of a barrel of Terumah about which a doubt arose, one to which a questionable event occurred. The case the Bartenura presents: two barrels of wine are before you, a dead mouse touched one of them, and it is not known which of the two it touched.
The Rules of Doubtful Tumah:
The standard rule in cases of doubtful tumah, in situations where the transmission of tumah is uncertain, is an overarching principle that governs a great many scenarios:
"birshus harabim" - a public domain, a place where people are found, more than two people who come there: we resolve the doubt leniently and rule that it is tahor.
"birshus hayachid" - a private domain, a place where two people or fewer are found: we rule stringently and assume that it is tamei.
The source of this rule is a derashah from the parashah of sotah, and although that subject is beyond the scope of our discussion here, it is the classic case in the Torah in which it is not known whether the woman was unfaithful or not, and it will never be known. Even so, there is a basis for assuming that she acted improperly: her husband had already warned her not to seclude herself with that man, and nevertheless she went and secluded herself with him. The Torah defines such a woman as tamei - a puzzling choice of language, since she is not actually tamei; rather, we rule stringently that she is forbidden to her husband until the sotah process is carried out and the matter is clarified. The very use of the term "tamei" is expounded to teach that a doubt about tumah that arose in a private domain, in a scenario of two people or fewer, is ruled to be tamei; whereas in a public place - where, had the sotah been there, there would have been no problem of seclusion at all - we rule leniently.
In light of this, the rule is that a doubt about tumah that arose in a public domain is ruled tahor, and in a private domain tamei. But we have already seen in this masechta that if applying the rules for resolving a doubt forces us to live a lie, we do not follow them, even though ordinarily we would rule stringently. For when there are two barrels and it is known with certainty that the dead mouse touched only one of them, giving both barrels the same ruling, whether in a public domain or in a private domain, forces us to live a lie. In the case brought by the Bartenura, which occurred in a private domain, we would rule that the barrels are tamei and treat both of them as tamei - and by doing so we are living a lie, since one barrel is certainly tahor.
And with Terumah an interesting point is added: here there is no clear definition at all of what constitutes leniency or stringency in matters of tumah and taharah. Why? Because ruling that the Terumah is tamei gives it a new status - Terumah that became tamei must be destroyed. On the other hand, as we see in our Mishnah, there is a mitzvah to safeguard Terumah, and it is forbidden by Torah law to destroy Terumah that is tahor; rather, there is an obligation to eat it. It emerges that you cannot hold on to both sides: if you assume it is tamei, you will be forced to destroy it; and if you assume it is tahor, you will be forced to eat it. Therefore there is no clear ruling of lenient or stringent regarding doubtful Terumah: if you eat it, perhaps that is forbidden; and if you destroy it, perhaps that too is forbidden. In such a situation a person is stuck, and this is the case our Mishnah deals with - a case in which we cannot use the ordinary rules of doubt to determine the status. We have two barrels before us, and with both of them we wish to be stringent, but there is no clear ruling as to how to be stringent.
The words of the Mishnah:
"Chavis shel Terumah shenolad bah safek tumah" - a barrel of Terumah about which a doubt arose concerning its tumah status, such as where a dead mouse touched one of two barrels.
"Rabbi Eliezer omer, im haysah munachas bimkom hatorfah, yanichenah bimkom hamutzna" - Rabbi Eliezer follows his own approach, that "terumosai" teaches about two types of Terumah that require safeguarding, the second type being suspended Terumah, which is of doubtful tumah status. Therefore one is obligated to protect it from further exposure to tumah, and if the barrels were resting in a place where they are exposed to contracting tumah because it is unprotected, one is obligated to move them to a protected place.
The wording of the Mishnah is "mekom hatorfah," and "torfah" is an unusual word whose meaning is something open to damage, available for bad things to happen to it because it is not properly protected. In our context it refers to an ownerless place that no one is watching over, and therefore dead mice and the like are liable to reach the barrel quickly. In such a situation - "yanichenah bimkom hamutzna": there is a Torah mitzvah, by force of "terumosai," to safeguard suspended Terumah as well, and to move it from the exposed place to a concealed place that is better protected from further exposure to tumah.
"Im haysah megulah" - Rabbi Eliezer adds that if the barrel of Terumah was open, and as we saw regarding "giluy" in the previous mishnayos it is exposed to snakes drinking from it and the like, one may not leave it that way, but rather "yechasenah" - one is obligated to cover it so that it will not be exposed and lost, but will be safeguarded.
Rabbi Yehoshua says the opposite. In his view, since the verse is pronounced "terumosai" but written "terumasi," there is only one type of Terumah that requires safeguarding - Terumah that is certainly tahor; whereas suspended Terumah, which is doubtful Terumah, need not be safeguarded. And since he is concerned that if it remains rolling around in the vicinity a mishap will eventually occur and people will eat from it, and that eating may involve a Torah prohibition, since it may well have become tamei through contact with the dead mouse - he seeks to speed up the process that will allow it to be disposed of with certainty. Therefore we want a second dead mouse to fall into it, or a snake to drink from it, and the like. For this reason Rabbi Yehoshua says: "Im haysah munachas bimkom hamutzna, yanichenah bimkom hatorfah" - it should be left outside and exposed to mishap, so that something bad will happen to it and then he will be able to pour it into the sewer; "im haysah mechusah, yegalenah" - he should open it.
It is worth noting that I do not find commentators who address the matter of giluy, that is, that the exposure is intended so that snakes will drink from it, and therefore it is not entirely clear to me whether this is the Mishnah's intent, although it appears so to me. And if not, the intent is to expose it so that tumah will reach it, and in this way the process will be sped up and it will be possible to be rid of this doubtful Terumah as quickly as possible.
Rabban Gamliel holds an intermediate position: "al yechadesh bah davar" - one should do nothing. It should not be moved from its place, it should not be covered, and it should not be uncovered. Although he agrees with Rabbi Yehoshua that there is no obligation to safeguard doubtful Terumah, nevertheless there is certainly the possibility that it is tahor, and by hastening its becoming tamei a person is doing something bad. Therefore one should sit passively and do nothing, and in the end, once it becomes exposed to tumah, he will be able to be rid of it. And the halachah follows Rabban Gamliel.
In summary: In this Mishnah we learned three approaches to the law of a barrel of Terumah in which a doubt of tumah arose, all resting on a dispute over the exposition of "mishmeres terumosai": Rabbi Eliezer, who expounds "yesh eim la'mikra" (we follow the way the word is read), requires guarding even Terumah whose status is in doubt, and therefore instructs that it be put away in a protected place and covered; Rabbi Yehoshua, who expounds "yesh eim la'masores" (we follow the way the word is written), exempts it from guarding and instructs that its becoming tamei be hastened so as to be rid of it; and Rabban Gamliel rules that nothing new should be done with it, and the halachah follows his view.