Does an oath need to be expressed in words or can one just decide in one’s mind? Does an oath of expression apply only also to a mitzva? There is a debate in the mishna regarding this and there is a discussion regarding the proofs for each side. If one takes an oath that repeats itself without adding on something new, the subsequent oaths are not valid and if one breaks them accidentally,one would be only obligated to bring one sacrifice. However, if the person were to go to a ‘chacham’ to repeal the oath, the second oath would be apply.