Purification (Kitab Al-Taharah) 
Dawud :: Book 1 : Hadith 203
Narrated Ali ibn AbuTalib:
The Apostle of Allah (peace_be_upon_him) said: The eyes are the leather strap of the anus, so one who sleeps should perform ablution.
Purification (Kitab Al-Taharah)
Dawud :: Book 1 : Hadith 203
Narrated Ali ibn AbuTalib:
The Apostle of Allah (peace_be_upon_him) said: The eyes are the leather strap of the anus, so one who sleeps should perform ablution.