What is the ruling on feeding the poor as expiation for not fasting Ramadan for those prevented from fasting due to illness, what is the measure of a saa', and must the father give it out?

If your illness is one from which recovery is hoped for, then you must make up the fasts after recovery. However, if your illness is one from which recovery is not hoped for, then you must feed one poor person for each day you break your fast. The amount of food to be given is a mudd (approximately 750 grams) or half a sa' (approximately 1.5 kilograms, which is more cautious). The fidyah must be paid from your own money. If you do not have money, the fidyah remains a debt upon you until money becomes available, and you are not required to pay it immediately. It is permissible for your father to pay the fidyah on your behalf if you authorize him or if he knows of your intention to pay it beforehand.