unless the verse specifies that one is liable only if he curses both together. An example of a verse where the Torah specifies that the halakha applies only to the two elements in conjunction is: “You shall not plow with an ox and a donkey together” (Deuteronomy 22:10).

The Gemara continues: You may even say that the verse is referring to optional matters according to the opinion of Rabbi Yoshiya. He holds in accordance with the opinion of Rabbi Akiva, who interprets the Torah using the hermeneutical principle of amplifications and restrictions (see 26a), and the word “or” is superfluous and is used to separate “to do evil” from “to do good.”

The Gemara explains how one derives that the oaths referred to in the verse are oaths about optional matters in accordance with Rabbi Yoshiya, who interprets the verse in accordance with the principle of amplifications and restrictions: Granted, if you say that the verse about an oath on an utterance is written with regard to optional matters, the words “to do evil, or to do good” serve to restrict the meaning of the verse and exclude the application of an oath on an utterance to a matter involving a mitzva. The Gemara asks rhetorically: But if you say that the verse is written referring to a matter involving a mitzva, what do the words “to do evil, or to do good” serve to restrict?

§ The mishna teaches: Rabbi Yehuda ben Beteira said: What? If, with regard to an oath concerning an optional matter, for which one is not under oath from Mount Sinai, he is liable for breaking it, then with regard to an oath about a mitzva, for which he is under oath from Mount Sinai, is it not logical that he would be liable for breaking it? The Rabbis then asked him why he thinks one should be liable for an oath about a mitzva, since one would be exempt if it were inverted from positive to negative, rendering it an oath to refrain from performing a mitzva, which does not take effect. The Gemara comments: The Rabbis’ objection to the opinion of Rabbi Yehuda ben Beteira is well stated.

The Gemara responds: And Rabbi Yehuda ben Beteira could say to you: Isn’t there the case of an oath involving doing good to others, even though it does not include the possibility of being inverted to include liability for an oath concerning harming others, but nevertheless the Merciful One has amplified the halakha to include it? Here also, with regard to an oath to perform a mitzva, even though it does not include the possibility of being inverted to include liability for an oath concerning refraining from performing a mitzva, the Merciful One has amplified the halakha to include it.

And how could the Rabbis respond? They could say that there, with regard to an oath to do good to others, there is the possibility of inverting the oath to: I will not do good. Here, with regard to an oath to perform a mitzva, is there any possibility of a valid oath: I will not perform a mitzva?

MISHNA: If one says: On my oath I will not eat this loaf, and he then says again: On my oath I will not eat it, and again: On my oath I will not eat it, and he then ate it, he is liable only once. Once the first oath had taken effect, the subsequent oaths could not, as a prohibition cannot take effect where another prohibition is already in place.

This is an oath on an utterance, for which one is liable to receive lashes for intentionally breaking it, and for unwittingly breaking it one is liable to bring a sliding-scale offering.

For an oath taken in vain, one is liable to receive lashes when it is taken intentionally, and one is exempt when it is taken unwittingly.

GEMARA: The Gemara asks: Why do I need to teach the mishna such that the wording of the first oath is: On my oath I will not eat this loaf, and then the wording of the second oath is: On my oath I will not eat it?

The Gemara answers: This teaches us that the reason that he is liable only once is that he said: I will not eat this loaf, and then said: I will not eat it. But if he had said: I will not eat it, and then had said: I will not eat this loaf, he would be liable twice.

This is in accordance with the opinion of Rava, as Rava says: If one says: On my oath I will not eat this loaf, once he has eaten an olive-bulk of it he is liable, as this oath is understood to mean that it is prohibited for him to eat any of the loaf. If he says: On my oath I will not eat it, he is not liable unless he eats the whole loaf. The words: I will not eat it, indicate that his oath applies only to eating the entire loaf. Accordingly, when the first oath is: I will not eat it, and the second oath is: I will not eat this loaf, the second oath can take effect, as it generates a new prohibition that applies to each and every olive-bulk of the loaf.

§ The mishna teaches: If one says: On my oath I will not eat this loaf, and he then says again: On my oath I will not eat it, and again: On my oath I will not eat it, and he then ate it, he is liable only once. The Gemara asks: Why do I need the mishna to mention this additional, third, oath: I will not eat it?

The Gemara answers: This teaches us that there is no liability where one states redundant oaths, but there is an oath; the final oath is not completely discounted, so that if you find room, i.e., an application, for the additional oath, it goes into effect.

For what matter is this halakha relevant? It is relevant for the statement of Rava, as Rava says that if one requested of a halakhic authority to dissolve the first oath, and he did so, the second one counts for him in its place unless it, too, was dissolved.

The Gemara suggests: Let us say that the following baraita supports his opinion: With regard to one who took two vows of naziriteship, and counted the first term of naziriteship and separated an offering for it, and afterward requested and received dissolution of the first vow from a halakhic authority, the second term was counted for him in the observance of the first term, and he is not required to be a nazirite further. This indicates that the second vow went into effect retroactively once the first was dissolved, and the same would be true in the case of two oaths.

The Gemara rejects this: How can these cases be compared? There, the second naziriteship is there in any event, as once he counts the first term, he needs to return and count the second if there is no request for dissolution. Here, if he does not request dissolution of the first oath, is there a second oath at all? Therefore one cannot find support for Rava’s opinion from the baraita.

§ Rava says: If one took an oath about a loaf and then ate it, if he left an olive-bulk of it, he may request that his oath about the loaf be dissolved. If he ate the whole loaf, he may no longer request that his oath about it be dissolved.

Rav Aḥa, son of Rava, said to Rav Ashi: What are the circumstances? If one took an oath where he said: I will not eat this loaf, which Rava, as cited above, understands as rendering it prohibited for him to eat any part of the loaf, then with the first olive-bulk that he ate he already committed his transgression. If he took an oath where he said: I will not eat it, which Rava understands as rendering it prohibited for him to eat only the whole loaf, why does Rava mention specifically that he left over an olive-bulk?