IMPORTANCE OF SALAH

Narrated `Imran bin Husain: I had piles, so I asked the Prophet (ﷺ) about the prayer. He said: “Pray while standing and if you can’t, pray while sitting and if you cannot do even that, then pray lying on your side.”

عَنْ عِمْرَانَ بْنِ حُصَيْنٍ ـ رضى الله عنه ـ قَالَ كَانَتْ بِي بَوَاسِيرُ فَسَأَلْتُ النَّبِيَّ صلى الله عليه وسلم عَنِ الصَّلاَةِ فَقَالَ صَلِّ قَائِمًا، فَإِنْ لَمْ تَسْتَطِعْ فَقَاعِدًا، فَإِنْ لَمْ تَسْتَطِعْ فَعَلَى جَنْبٍ

[Sahih Al-Bukhari, Shortening the Prayers (At-Taqseer), Hadith: 1117]
Chapter: Whoever cannot offer Salat while sitting, can offer Salat while lying on his side.