Is an oath, uttered involuntarily with the intention of persuading one's mother to wait, considered a binding oath if not fulfilled?

The apparent meaning of the questioner's statement, "involuntarily," indicates that he did not intend to form an oath with it. Rather, this utterance came from him without the intention of swearing. This is considered a 'laghw al-yamin' (idle oath), which does not necessitate expiation, because the preponderant opinion is that whatever is uttered unintentionally is considered an idle oath.