His father is suffering from an illness close to paralysis and has remained in the hospital for three months. Is it permissible to pray on his behalf, and what is the ruling regarding fasting?

Question:
He says: He has a father who is ill, approximately sixty-five years old, suffering from diabetes and high blood pressure, and afflicted with an illness close to paralysis. He was hospitalized for three months, including the month of Ramadan. It appears that he did not pray during that period. He asks about the prayer and fasting: Shaykh Salih, may Allah preserve him, should he pray on his behalf, or how do you advise him? May Allah reward you with good.

Answer:
The sick person prays according to his condition, and it is not permissible for him to abandon the prayer as long as his mind is intact. However, he prays according to his condition: standing, sitting, on his side, or lying on his back. If he is able to perform the purification required of him, he does so; otherwise, he performs tayammum (dry ablution) with dust. This is based on the saying of the Exalted and Majestic: "Fear Allah as much as you are able" and "Allah does not charge a soul except with what it can handle." It is also based on the saying of the Prophet (peace and blessings be upon him): "The one who is sitting prays standing; if he cannot, he prays sitting; if he cannot, he prays on his side." If he prays on his side or lying on his back, he indicates the ruku' (bowing) and sujud (prostration) with his head, and he makes his sujud more distinct than his ruku'. It is not permissible for him to abandon the prayer as long as he is of sound mind. Many people make a mistake in this matter, thinking that a patient who is hospitalized does not pray and delays the prayer until he is discharged. This is a great error, because abandoning the prayer is not permissible, as it is the second pillar of the pillars of Islam, and because it is performed according to one's ability, as we have heard. The healthy person has a specific way of praying, and the sick person has a specific way of praying. Each person prays. The fearful person has a way of praying, and the secure person has a way of praying. The traveler has a way of praying, and the resident has a way of praying. This indicates that the prayer is not dropped under any circumstances; rather, the Muslim prays it according to his condition and his capacity.
No one prays on behalf of another, because the prayer does not admit of delegation, as it is a physical act. If he is able to make up what he missed, it is obligatory for him to make up what he left, even if the making up is delayed. If he recovers and is able to make up the prayers, he makes them up, and he is never prayed for by another. If he dies without having made up the prayers, his case is left to Allah the Exalted and Majestic, but no one prays on his behalf. As for fasting, if he is able to make up the fasts, he does so. If he is unable to make them up because the illness continues with him, and it is a chronic illness, diabetes for which no cure is expected, then he feeds a poor person for each day. The amount is half a sa' of food, which is one and a half kilograms for each day. It is permissible to pay this to several poor people or to one poor person by collecting it. It is permissible to pay it in separate portions, to pay it in a lump sum, and to pay it to several poor people or to one poor person. Yes. May Allah reward you with good, and may He do you good.