Study Shevuot folio 27A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Text Excerpt
מתני׳ נשבע לבטל את המצוה ולא ביטל – פטור. לקיים ולא קיים – פטור; שהיה בדין שיהא חייב, כדברי רבי יהודה בן בתירא.
Mishnah: If one takes an oath to refrain from performing a mitzva and he does not refrain, he is exempt from bringing an offering for an oath on an utterance. If he takes an oath to perform a mitzva and he does not perform it, he is also exempt, though it would have been fitting to claim that he is liable to bring the offering, in accordance with the statement of R' Yehuda ben Beteira.
אמר רבי יהודה בן בתירא: מה אם הרשות, שאינו מושבע עליו מהר סיני – הרי הוא חייב עליו; מצוה, שהוא מושבע עליה מהר סיני – אינו דין שיהא חייב עליה?!
The Mishnah explains: R' 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?
אמרו לו: לא אם אמרת בשבועת הרשות – שכן עשה בה לאו כהן, תאמר בשבועת מצוה – שלא עשה בה לאו כהן; שאם נשבע לבטל ולא ביטל – פטור.
The Rabbis said to him: No, if you said that one is liable for breaking an oath concerning an optional action, where the Torah rendered one liable for a negative oath not to perform it like for a positive oath to perform it, should you also say one is liable with regard to breaking an oath concerning a mitzva, where the Torah did not render one liable for a negative oath like for a positive oath, since if one takes an oath to refrain from performing a mitzva and did not refrain, he is exempt.
גמ׳ תנו רבנן: יכול נשבע לבטל את המצוה ולא ביטל, יהא חייב? תלמוד לומר: ״להרע או להיטיב״ – מה הטבה רשות, אף הרעה רשות; אוציא נשבע לבטל את המצוה ולא ביטל, שהוא פטור.
Talmud: A baraita states: One might have thought that when one takes an oath to refrain from performing a mitzva and he does not refrain, he would be liable to bring an offering for an oath on an utterance. To counter this, the verse states: “To do evil, or to do good” (Leviticus 5:4). Just as doing good is referring to an oath about an optional action, so too, doing evil is referring to an oath about an optional action. I will therefore exclude from liability one who takes an oath to refrain from performing a mitzva and does not refrain, so that he is exempt from bringing the offering.