Does the oath of one jesting become binding if it was uttered in the course of his speech and he did not intend it?

A jesting oath uttered unintentionally and without deliberate purpose is not binding. It carries no expiation or accountability because it falls under the category of a 'vain oath' (laghw al-yamin). Ibn Qudamah and Al-Nawawi both indicated that the words of Aisha suggest that vain oaths are those made in argumentation, jesting, amusement, or casual conversation, where the heart does not intend to affirm or bind itself.