Is it necessary to complete the fasting for an expiation of an oath if the money becomes available to feed the needy after one has started fasting?

The expiation for an oath is to feed ten poor persons, or to clothe them, or to free a slave. Whoever cannot find [the means to do so] must fast for three days. If one begins fasting due to inability to perform the three aforementioned acts, and then becomes able to perform one of them, the majority of scholars hold that it is not obligatory for him to revert to it. However, if he wishes to do so, there is no harm, as it is a transition to what is higher and more perfect.