Shevuot 53
<big><strong>מתני׳</strong></big> נשבע לבטל את המצוה ולא ביטל פטור לקיים ולא קיים פטור שהיה בדין שיהא חייב כדברי ר' יהודה בן בתירא
<br> MISHNAH. IF HE SWORE TO ANNUL A PRECEPT, AND DID NOT ANNUL IT, HE IS EXEMPT; TO FULFIL [A PRECEPT], AND DID NOT FULFIL IT, HE IS EXEMPT; THOUGH LOGICALLY [IN THE SECOND INSTANCE] HE SHOULD HAVE BEEN LIABLE, AS IS THE OPINION OF R. JUDAH B. BATHYRA: [FOR] R. JUDAH B. BATHYRA SAID: NOW, IF FOR AN OPTIONAL MATTER, FOR WHICH HE IS NOT ADJURED FROM MOUNT SINAI, HE IS LIABLE; FOR A PRECEPT, FOR WHICH HE IS ADJURED FROM MOUNT SINAI, HE SHOULD MOST CERTAINLY BE LIABLE! THEY REPLIED TO HIM: NO! IF YOU SAY THAT FOR AN OATH IN AN OPTIONAL MATTER [HE IS LIABLE]. IT IS BECAUSE [SCRIPTURE] HAS IN THAT CASE MADE NEGATIVE EQUAL TO POSITIVE [FOR LIABILITY]; BUT HOW CAN YOU SAY THAT FOR AN OATH [TO FULFIL] A PRECEPT [HE IS LIABLE], SINCE [SCRIPTURE] HAS NOT IN THAT CASE MADE NEGATIVE EQUAL TO POSITIVE, FOR IF HE SWORE TO ANNUL [A PRECEPT], AND DID NOT ANNUL IT, HE IS EXEMPT! GEMARA. Our Rabbis taught: I might think that if he swore to annul a precept, and did not annul it, he should be liable, therefore it is said: to do evil, or to do good; just as doing good is optional, so doing evil must be optional; I must therefore exclude: if he swore to annul a precept, and did not annul it; for which he is exempt. I might think that if he swore to fulfil a precept, and did not fulfil it, he should be liable, therefore it is said: to do evil, or to do good; just as doing evil is optional, so doing good must be optional; I must therefore exclude: if he swore to fulfil a precept, and did not fulfil it; for which he is exempt. <br>
א"ר 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
I might think that if he swore to do evil to himself, and did not do so, that he should be exempt, therefore it is said: to do evil, or to do good; just as doing good is optional, so doing evil must be optional; I will therefore include: if he swore to do evil to himself, and did not do so, [that he is liable,] for the option is in his own hands. I might think that if he swore to do evil to others, and did not do so, that he should be liable, therefore it is said: to do evil, or to do good; just as doing good is optional, so doing evil must be optional. I will therefore exclude: if he swore to do evil to others, and did not do so, [that he is exempt], for the option is not in his hands. Whence do we know to include [an oath] to do good to others? Because it is said: or to do good. And what is doing evil to others? T shall smite So-and-so, and crack his brain.'
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:
But how do we know that the verses refer to optional matters, perhaps they refer [also] to matters relating to precepts? - That cannot enter our minds, for we require that doing good shall be similar to doing evil, and that doing evil shall be similar to doing good; for [the verse] likens doing evil to doing good: just as doing good cannot refer to the annulling of a precept, so doing evil
<big><strong>גמ׳</strong></big> ת"ר יכול נשבע לבטל את המצוה ולא ביטל יהא חייב ת"ל (ויקרא ה, ד) להרע או להיטיב מה הטבה רשות אף הרעה רשות אוציא נשבע לבטל את המצוה ולא ביטל שהוא פטור
cannot refer to the annulling of a precept; [so that this] doing evil is actually doing good! And it likens doing good to doing evil; just as doing evil cannot refer to the fulfilling of a precept, so doing good cannot refer to the fulfilling of a precept; [so that this] doing good is actually doing evil! If so, even in an optional matter it is not possible! - Well then since [the word] 'or' is necessary in order to include doing good to others, we deduce that the verses refer to optional matters, for if it should enter your mind that they refer to matters relating to precepts [we would not require the word 'or' to include doing good to others for], since doing evil to others is included, doing good is certainly [included]!
יכול נשבע לקיים את המצוה ולא קיים שיהא חייב ת"ל להרע או להיטיב מה הרעה רשות אף הטבה רשות אוציא נשבע לקיים את המצוה ולא קיים שהוא פטור
But this [word] 'or' is necessary to separate [the phrases]? - To separate them the word is not necessary. That is so, according to R. Jonathan, but according to R. Josiah, what is to be said? For it has been taught: A man who curseth his father or his mother [shall surely be put to death]; from this we know only [if he curses] his father and his mother; [if he curses] his father and not his mother, or his mother and not his father, how do we know [that he is liable]? Because it is [also] said: His father or his mother he hath cursed; his father he hath cursed, his mother he hath cursed. This is the opinion of R. Josiah. R. Jonathan said: It may imply both together, and it may also imply each one alone