Is it permissible to fast on behalf of someone who has been struck by a severe illness that has confined them to bed for a long period and left them unable to move?

Question:
One of the brothers sent you a question, and in it he says: Shaykh Abu 'Umar, my father was struck by a severe illness that confined him to bed for five years, and always, Honorable Shaykh, he is unable to move. We tell him that the time for prayer has come, and he only shakes his head and does not speak. Do we fast on his behalf? Do we pray on his behalf? What should we do? May Allah reward you.

Answer:
As for fasting, he fasts, he fasts. As long as Allah heals him and he is able to fast, he fasts. As for the prayer, no one prays on behalf of another. So if he left off the prayer because he is unable to pray, and he has no presence of heart and no intellect, then there is no prayer required of him. But if he understands what he says, understands the time of prayer, and knows the time of prayer, then he must pray. If he left off any of it, he must make it up, and it is obligatory for him to do so. Yes.