If a person breaks his oath, then the expiation (Kaffarah) for the oath becomes obligatory upon him, and it is as follows: feeding ten needy persons (Misakeen) two meals, or providing them with clothes, or freeing a slave. He has the choice among these three; he may pay the expiation with whichever he wishes. And if he does not have the ability to do any one of these three, then he should fast for three consecutive days.
Some people, despite having the ability to feed or provide clothes, pay the expiation for their oath by fasting for three days, and thus think that their expiation has been fulfilled, whereas the correct ruling is that the expiation has not been fulfilled. Because for the payment of expiation through fasting to be valid, being unable to feed and clothe is a condition. (Aham Masail / Vol: 3 / Page: 206)