What is the expiation for repeated oaths that one has broken, the exact number of which is unknown, and for which one is unable to fast the required number of days?

Excessive swearing may lead to embarrassment or a diminished regard for oaths sworn by Allah. Allah Almighty has commanded the preservation of oaths and condemned those who swear excessively. Swearing by anything other than Allah is not permissible. Therefore, whoever swears by other than Allah, such as swearing by what is forbidden (haram), must frequently seek forgiveness and repent sincerely. If the one who swears by what is forbidden has a wife, the preponderant opinion is that he is considered to have committed ẓihār against her, and a single ẓihār expiation suffices, even if the oath is repeated before it is offered. However, if he does not have a wife, the preponderant opinion is that an expiation for a broken oath (kaffārat yamīn) is required of him.