Whoever is unable to stand prays seated, bowing and prostrating.
تحفة الملوكZayn al-Dīn al-Rāzīفصل في المريض
Chapter on the sick person
If he cannot bow or prostrate, he gestures seated, making prostration lower than bowing, and raises nothing to his face to prostrate on.
If he cannot sit, he lies on his back with feet towards the qibla and gestures bowing and prostration; or lies on his sides facing it—the former is likelier.
فإن لم يطق الإيماء برأسه، أخَّرَ الصلاةَ، ولم تسقط ما دام مفيقاً، ولا يومئ بغير رأسه.
If he cannot gesture with his head, he delays the prayer; it is not dropped while he is conscious; he does not gesture with other than his head.
وإن قدرَ على القيام لا على الرّكوع والسّجود، صَلَّى قاعداً يومئ بهما، أو قائماً، والأَوّل أولى.
If he can stand but not bow or prostrate, he prays seated gesturing them, or standing—the former is likelier.
ومَن مرضَ في صلاته بنى على حسب ما يقدر.
Whoever falls ill during prayer builds according to his ability.
ومَن صَلَّى قاعداً، ثم صحَّ بنى قائماً.
Whoever prayed seated then recovered builds standing.
وإن صَلَّى مومئاً، ثم صحَّ فيها استقبل.
If he prayed gesturing then recovers during it, he repeats.
ومَن جنَّ أو أغمي عليه يوماً وليلةً، قضى بخلاف الأكثر.
Whoever is insane or unconscious a day and night makes up—against the majority on the insane case.
والنائم يقضي مطلقاً.
The sleeper always makes up.
ويقضي المريض فائتةَ الصحّةِ على حسبِ حاله، ويقضي الصحيح فائتة المرض كاملة.
The sick person makes up what health missed according to his state; the healthy person makes up what illness missed in full.