It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Whoever falls asleep in the state of prostration, there is no ablution upon him; ablution is required for the one who sleeps lying down, because when a servant sleeps lying down, his joints become loose and relaxed.
Hadith Takhrij«اسناده ضعيف، يزيد بن عبد الرحمن مختلف فيه۔ أخرجه ابوداود: 202، والترمذي: 77 ، (انظر مسند أحمد ترقيم الرسالة: 2315 ترقیم بيت الأفكار الدولية: 2194»
Brief Explanation
Benefits: … This hadith, as well as all those narrations in which a distinction is made between sitting and lying down while sleeping, are weak.