Is it permissible to feed domestic workers as part of an atonement for an oath, and is it valid to divide the feeding over several days with the same person repeatedly?

If the workers are poor and you are not obligated to support them, then it is permissible to feed seven of them and complete the remaining ten with others to fulfill the required number for the expiation of an oath. It is also permissible to feed the ten on separate days. However, if they are not poor, or if their support is obligatory upon you, then paying the expiation to them is not sufficient.