i have a question on daf b amud b. according to sumchos, the problem is that he makes a shevuat shav. so according to the answer the gemara gives it doesnt make sense to me. if he swears truthfully and we force him to swear and he gets half of it anyway then isnt it still a shevuat shav. not that he lying but stating the obvius for no reason ?
Arye
I am not sure I understand your question. I suppose you mean Ben Nanas, not Sumchus. And you may be asking why the Mishnah makes each of the people holding the Talis swear. We should just give them the Talis without a Shevu'ah, since even if the Shevu'os of both of them are true, they are not accomplishing anything and therefore are extraneous.
This is not so. Every Shevu'ah administered by Beis Din accomplishes something, and is not extaneous. We do not know if one of the people holding the Talis is an intentional liar, and the Shevu'ah persuades the liar -- if there is one -- to back out and admit to the truth, rather than swearing falsely. Do not assume that the two people holding the Talis must be Tzadikim -- the Gemara in fact concludes (3a) that we are afraid "every person will go and grab the Talis of his neighbor and claim it as his."
Be well,
Mordecai Kornfeld