A nazir who was in doubt whether he was tamei and in doubt [also] whether he was a confirmed [metzora] —- he may eat sacred foods after sixty days, and drink wine and contaminate himself with the tumah of the dead after one hundred and twenty days, because shaving for the affliction [of tzaraas] overrides shaving for nezirus when [the former] is certain, but when it is doubtful it does not override it.