Fiqh-us-Sunnah, Volume 2: The prayer of a person who is ill (Salatul Marid)
Whoever has some excuse due to illness and cannot stand during the fardsalah is allowed to pray sitting. If he cannot pray in a sitting posture, hemay pray while on his side by making gestures. In such a case, his gestures forsajdah should be lower than those for his ruku'. This principle is based onAllah's words: "...And celebrate Allah's praises, standing, sitting, andlying on your sides."
'Imran ibn Hussain says: "I had piles [hemorrhoids], so I asked theProphet about the prayer and he said: 'Offer the salah while standing and ifyou cannot do so, pray while sitting, and if you can't do that, then make salahwhile Iying on your side."' This is related by the group, except forMuslim. An-Nasa'i adds: "And if you cannot offer salah while lying on yourside, then do it while lying on your back. Allah does not burden a soul, save withwhat it can bear."
Jabir reports: "The Messenger of Allah visited a sick person and foundhim praying on a cushion. The Prophet pushed it aside and said: "Pray onthe ground if you can, and if you cannot, then pray by making gestures, andmake your sajdah lower than your ruku'.'" This is related by alBaihaqi .
What is meant by inability is that the person if he prays [in the regularway], will suffer hardship, or his disease will aggravate, or his recoverywould be hampered, or he will swoon if he prays in the customary manner. Oneshould sit cross-legged while praying in a sitting position.
'Aishah narrates that she saw the Prophet sallallahu alehi wasallam sittingcross-legged while praying. This is related by an-Nasa'i and al-Hakim says itis sahih.: It is also permissible to sit in the manner that one sits whileperforming the tashahud
One who can offer the salah neither sitting nor standing is to lie down onhis side, and if he cannot do that, he is to lie down on his back with his legstoward the qiblah according to his state of health. Ibn al-Munzhir prefers thisopinion. On this point, there is a weak hadith reported by 'Ali which statesthat the Prophet said: "The sick person is to pray standing if he is able.If he cannot do so, he should pray sitting. If he is not able to make thesajdah, he should nod with his head and make the nod of his sajjud lower thanthat of his ruku'. If he cannot pray in a sitting posture, he should pray whilelying down on his right side facing the qiblah. If one cannot pray on his rightside, he should pray while lying on his back with his legs stretched out towardthe qiblah." This is related by ad-Daraqutni. Some scholars maintain thatone can pray in whatever manner is easy for him. It is apparent from the hadiththat if one can only nod while lying on his back, then nothing else isobligatory upon him.