What is the ruling regarding someone who made a covenant with Allah to abandon a sin but then returned to it, and possesses only a small amount of money insufficient for expiation? Is it permissible for him to fast or to take food from his home to distribute among the needy?

If you do not own enough to feed ten needy persons or clothe them for an expiation of an oath, then you move to fasting, according to the Almighty's saying: "But whoever finds not [the means to do so] - then a fast of three days [is required]." It is permissible to take food from the house for expiation with your father's permission. It is more prudent to fast the three days consecutively, though if you separate them, it is permissible according to many scholars.