Please elaborate on the expiation for breaking an oath.

The expiation for an oath is feeding ten needy persons from the average food one provides to his family, or clothing them, or emancipating a believing slave. If one cannot find any of these, then he must fast for three consecutive days. The majority of scholars hold that it is not permissible to give the expiation in cash; rather, it must be in the form of food, clothing, or the emancipation of a slave.