גלגול שבועה

לרפואת אלתר שמעון יחזקאל בן רחל חנה בתוך שח"י  

A beloved friend and chavrusa emailed me a question today about גלגול שבועה so I thought that it would be a good opportunity and perhaps a sign from shomayim that I should share with the world a thought on the topic from moreinu vi-raboseinu.

What is גלגול שבועה?

גלגול שבועה does NOT mean that one's neshama gets another round in this world after dying previously in order to take an oath.

It does mean that if one is already obligated to take an oath over a monetary dispute [such as movable items] he may further be obligated to take an oath on something which normally doesn't require an oath [such as land]. Another example is that the court can make a woman take an oath that she was not a סוטה during the period of eirusin [normally not necessary] once she is already obligated to take an oath that she was not a סוטה during the period of nisuin.

The question is - what are the mechanics of גלגול שבועה?

Is it that the first oath is a reason to obligate [סיבה לחייב] a second oath or is it similar to what we find regarding brachos on food - the first oath is עיקר the primary obligation, and the second oath is טפל - secondary, ancillary and "dragged in" by the first oath [not getting into the mechanics of how עיקר and טפל work regarding food...].

Is this merely an academic question?

No. We are not academics and aren't bald with glasses at the end of our noses.

Big na"m [נפקא מינה] offered by the great gaon Rav Aharon Kotler ztz"l [Bava Matzia 15/4]: If the defendant agreed to pay instead of taking the first oath - is he still obligated in the second oath. If you learn the first way - then he is still obligated because there is a סיבה לחייב the second oath, namely the obligation of the first oath. But if you learn the second way, that the second oath is merely טפל to the first, then we say that if there is no עיקר then there is also no טפל and both oaths are off.

See also חידושי ר' שמואל בב"מ עמ' ס"ז.