Nedarim

GEMARA. MORE RIGOROUS? That implies that they are [valid] vows;  but it is taught, He is permitted?  — This is taught in reference to the second clause of the other section: [viz.,] [If one says,] ['I swear] on oath not to sleep,' or, 'talk,' or 'walk,' he is forbidden [to do so]: IN THESE INSTANCES OATHS ARE MORE RIGOROUS THAN vows. YET THERE IS GREATER STRINGENCY IN VOWS THAN IN OATHS etc. R. Kahana recited, R. Giddal said in Rab's name, and R. Tabyomi recited, R. Giddal said in Samuel's name: Whence do we know that one cannot swear [a valid oath] to violate the precepts? Front the verse, When a man … swear an oath … he shall not break his word,'  [this implies,] he may not break his word,  but he must break a word [i.e., an oath] in respect of Heavenly matters.  Now, why are vows different: because it is written, When a man vow a vow unto the Lord … he shall not break his word?  But [of] oaths too it is written, or swear an oath unto the Lord he shall not break his word?  — Abaye answered: In that case [vows] one says: 'The pleasure of the sukkah be forbidden me';  but in this case [oaths] one says; 'I swear that I shall not benefit from the sukkah'.  Raba objected: Were the precepts then given for enjoyment?  But Raba answered: There [in the case of vows] one says, 'The sitting in the sukkah be forbidden me';  but here [oaths] one says, 'I swear not to sit in the sukkah'. Now, do we learn that one cannot swear to transgress the precepts from this verse: do we not rather deduce it from elsewhere? For it was taught: If one swears to annul a precept, and does not, I might think that he is liable,