What is the considered amount for feeding the poor in expiation for breaking an oath, and is it permissible to suffice with rice, and what is the considered weight of a bag of rice, and is it sufficient to feed the poor person lunch and dinner, and is it permissible to give food to the head of the family on behalf of his family, and what is the considered number for a family, and is the age of the individual taken into consideration?

The meaning of "average" (أَوْسَط) in the verse: "from the average of what you feed your own families" refers to what is between extravagance and miserliness. Rice is among the average of what people eat, and it is sufficient to restrict the feeding to it, though with a side dish it is better. The amount of feeding is a matter of scholarly disagreement: some consider it to be one mudd of food (like the Shafi'is and Malikis), others consider it one mudd of wheat and half a saa' of other foods (the Hanbalis), and still others consider it half a saa' of wheat and one saa' of other foods (the Hanafis). Expiation is measured by volume, not by weight. Feeding a poor person lunch and dinner is required if they do not possess the sufficient amount, but if they do, it suffices. Ownership is not a condition for sufficiency; what matters is the feeding itself. The feeding can be done by preparing food for ten poor persons and inviting them, or by estimating one kilogram of rice for each poor person along with a side dish. It is permissible to give the sufficient amount to a head of a household consisting of ten individuals, or to a head of a household with fewer members until the number of ten is complete, whether they are children or adults who eat food. As for those who do not eat food, such as infants, the preponderant opinion is that giving it to them is not sufficient.