أنِینُ المُؤمِنِ المَریضِ تَسبِیحٌ، و صِیاحُهُ تَهلِیلٌ، و نَومُهُ عَلَی الفِراشِ عِبادَةٌ. The groan of a sick believer is God`s praise, his shout is the mention of La ilaha illa Allah and his resting in the bed is prayer.
Bihar al-Anwar, Vol 77, Hadith 57
Rasul Allah Hazrat Muhammad (Peace and blessings of Allah be upon him and his progeny)Hadith