MISHNA: In a case where witnesses testify that there are two women who were taken captive, and this woman says: I was taken captive but I am pure, and that woman says: I was taken captive but I am pure, they are not deemed credible. And when this woman testifies about that woman that she is pure and vice versa, they are deemed credible.

GEMARA: The Sages taught in the Tosefta (2:2): If one of the women says: I am tainted and my counterpart is pure, she is deemed credible on both counts. If she says: I am pure and my counterpart is tainted, she is not deemed credible with regard to herself nor with regard to her counterpart. If she says: I and my counterpart are both tainted, she is deemed credible with regard to herself but she is not deemed credible with regard to her counterpart. If she says: I and my counterpart are both pure, she is deemed credible with regard to her counterpart but she is not deemed credible with regard to herself.

The Master said in the baraita that if she says: I am pure and my counterpart is tainted, she is not deemed credible. The Gemara asks: What are the circumstances? If there are no witnesses that she was taken captive, why is she not deemed credible with regard to herself? If she is saying: I was taken captive and I am pure, she is deemed credible based on the principle that the mouth that prohibited is the mouth that permitted. Rather, it is obvious that there are witnesses that she was taken captive.

The Gemara asks: If so, say the middle clause of the baraita: If she says: I and my counterpart are both tainted, she is deemed credible with regard to herself but she is not deemed credible with regard to her counterpart. And if there are witnesses, why is she not deemed credible with regard to her counterpart? Once there is testimony that she was taken captive, she no longer has the presumptive status of purity. Rather, it is obvious that there are no witnesses that she was taken captive, and therefore her presumptive status of purity is intact.

The Gemara asks: If so, say the last clause of the baraita: If she says: I and my counterpart are both pure, she is deemed credible with regard to her counterpart but she is not deemed credible with regard to herself. And if there are no witnesses that they were taken captive, why is she not deemed credible with regard to herself? Rather, it is obvious that there are witnesses.

The Gemara asks: Is that to say that the baraita is formulated in an unusual fashion, with the first clause and the last clause pertaining to cases where there are witnesses, and the middle clause pertaining to a case where there are no witnesses? Abaye said: Yes, the first clause and the last clause pertain to cases where there are witnesses, and the middle clause pertains to a case where there are no witnesses.

Rav Pappa said: The baraita in its entirety can be explained in a case where there are witnesses, and there is one witness who is testifying to the reverse of the woman’s claim. If the woman said: I am tainted and my counterpart is pure, and one witness said to her: You are pure and your counterpart is tainted, although the witness testified that she was pure, because she admitted that she was tainted she rendered herself an entity of prohibition. Her counterpart is permitted on the basis of her claim, which is accepted despite being contradicted by the witness.

If the woman said: I am pure and my counterpart is tainted, and one witness said to her: You are tainted and your counterpart is pure, then with regard to her, since there are witnesses testifying that she was taken captive, it is not in her power to permit herself on the basis of her claim. However, her counterpart is permitted on the basis of the testimony of the witness.

If the woman said: I and my counterpart are both tainted, and one witness said to her: You and your friend are both pure, she rendered herself an entity of prohibition. However, her counterpart is permitted on the basis of the testimony of the witness. The Gemara asks: Why do I need this additional case? This is identical to that which was taught in the in the first clause. The principles governing the first two cases, i.e., she claims that she is tainted and thereby renders herself as an entity of prohibition, and her counterpart is permitted by the testimony of one witness even if that testimony is contradicted, also apply in this case.

The Gemara answers: Lest you say that in this case, both of them are deemed untainted in accordance with the testimony of the witness, and the fact that she said that they are both tainted was because she was acting with the intention termed: “Let me die with the Philistines” (Judges 16:30), i.e., she was willing to implicate herself in order to bolster her credibility so that her testimony against her counterpart would be accepted, the tanna therefore teaches us that this is not a consideration.

If the woman said: I and my counterpart are both pure, and one witness said to her: You and your counterpart are both tainted, with regard to her, since there are witnesses testifying that she was taken captive, it is not in her power to permit herself on the basis of her claim. However, her counterpart is permitted on the basis of her claim. The Gemara asks: Why do I need this additional case? This is identical to that which was taught in the first part of the first clause. The principles governing the first two cases, i.e., her claim that she is pure is not accepted when the fact that she was taken captive was established by witnesses, and her counterpart is permitted on the basis of her claim even if that claim is contradicted, also apply in this case.

The Gemara answers: Lest you say that when is she deemed credible to permit her counterpart, it is only in a case where she rendered herself unfit to marry a priest, but in a case where she rendered herself fit, say that she is not deemed credible with regard to her counterpart; the tanna therefore teaches us that each segment of the testimony is assessed independently, based on the criteria taught in the first clause.

MISHNA: And likewise, with regard to two men whose lineage is unknown, and this man says: I am a priest, and that man says: I am a priest, they are not deemed credible. And when this man testifies about that man that he is a priest and vice versa, they are deemed credible. Rabbi Yehuda says: One does not elevate a man to priesthood on the basis of one witness. Two witnesses are required for that purpose. Rabbi Elazar says: When is that the ruling? In a case where there are challengers to his claim that he is a priest. However, in a case where there are no challengers, one elevates a man to priesthood on the basis of one witness. Rabban Shimon ben Gamliel says in the name of Rabbi Shimon, son of the deputy High Priest: One elevates a man to priesthood on the basis of one witness.

GEMARA: The Gemara asks: Why do I need all these different cases cited in the mishnayot in this chapter? Aren’t they all based on the principle: The mouth that prohibited is the mouth that permitted? The Gemara answers: These cases are all necessary, as, if the tanna had taught only the case where Rabbi Yehoshua concedes, in a case where one says to another: This field, which is currently in my possession, belonged to your father, and I purchased it from him, then one might have thought that his claim is deemed credible due to the fact that there is financial significance [derara] in his contention that it belonged to the other’s father, and he would not have made that claim if it were not true. However, in the case of witnesses authenticating their signatures, where there is no financial significance for them in their testimony, say no, their claim is not accepted.

And if the tanna taught only the case of witnesses, one might have thought that their claim is deemed credible due to the fact that their testimony is relevant to others. However, with regard to him, whose testimony is relevant to himself, as he claims that he purchased the field from the other’s father,