The oath of testimony applies to men but not to women, to non-relatives but not to relatives, to those qualified but not to those disqualified; and it applies only to those fit to testify; [both] in court and out of court —- by his own mouth; but if adjured by others —- they are not liable unless they deny [it] in court; [these are] the words of R' Meir. But the Sages say: Whether [he swears] by his own mouth or whether [he is adjured] by others —- they are not liable unless they deny it in court.