Shevuot 27: Oaths Regarding Mitzvot, Positive/Negative, Chosen/Obliged

Way back in Shavuot 22 we were introduced to the Mishna that we are continuing to learn today.  The rabbis are currently focusing on our Mishna's instruction to exempt a person who has sworn not to fulfil a mitzvah but then fulfilled it.  Similarly, it taught us that if one swore to fulfil a mitzvah and did not fulfill it, one is also exempt from liability.  The rabbis voice many different opinions about how this should be understood and applied.

Some of the points that we learn from these arguments:

• one could be obligated to fulfill one's promise based on the first hermeneutic principal of Torah study, kal v'chomer, simple and complex, also known as the principal of a fortiori, or 'all the more so'
• If one is liable to bring an offering based on reishut, voluntary acts unrelated to performing mitzvot, all the more should one be liable regarding keeping a mitzvah which was obligated to us on Sinai
• If this is a case of 'lehara o leheitiv", choosing evil or choosing good, it cannot be applied to the fulfilment of a mitzvah
• examples include one who swears to hurt oneself and does not keep one's oath; one who swears to hurt others and does not keep one's oath
• in both examples one is exempt because the oath was made in vain
• if one swears twice, for example "I swear I will not eat this loaf; I swear I will not eat it", one is only liable once if one transgresses
• cases might be discussing reishut or mitzvot
• the example of a person taking an oath of nazirut twice is contrasted

Of note are the rabbis' primary interests:

• is the action positive or negative?
• is the action voluntary or does it regard a mitzvah (an obligation)?
• in which order were the person's oath spoken?
• which principles might be applied to any statement in order to elucidate its meaning?
• what was the person's intent?

Clearly the rabbis wished to ensure that future judges would undergo their considerations with tremendous seriousness.