Does divorce take effect or is expiation obligatory for one who swears an oath of divorce unintentionally, and in the context of jest?

If an oath of divorce is uttered verbally without intent, it does not take effect. And if it does take effect and you fulfill your oath without breaking it, it also does not take effect. It should be noted that the only legitimate oath is by Allah Almighty. As for swearing by divorce, it is among the oaths of the dissolute.