Reish Lokish says: Hasroas Sofeik lo shma hasro'o. why is it a doubful hasro'o, is it because he may be shoel on the shvua at any moment?
if so how will reish lokish explain the mishna we just had in makos about nozir that as long as the eidim keep giving the nozir hasro'o, he keeps acumilating malkos.
But maybe he will be shoyel on his Nezirus? (The Ritva points this out later on the daf and answers that it is not an asroas sofek because it's not Beyodo, but what is Reish Lokish going to say?)
Rashi writes in Temurah (3b) that it is considered a Hasra'as Safek since whenever the Hasra'ah is given, the sinner can disregard it by saying that he still has time. When the day finally passes he can say that he forgot (since it is after Toch Kedei Dibur of the Hasra'ah).
i am sorry but i still dont understand if the hasra'ah is given at the very end of the day and they say to him you must do this "now" or you will be "over" is it still a safek ?
It is impossible to exactly pinpoint the moment that the day ends, and thus the Hasra'ah remains Hasra'as Safek. RASHI (21a, DH Hasra'as Safek) writes this explicitly.