النهي عن النوم على البطن
A specific discouragement of sleeping face-down, distinct from the existing entry on sleeping on the right side.
إِنَّ هَذِهِ ضِجْعَةٌ يُبْغِضُهَا اللَّهُ
“This is a lying position that Allah hates.” (meaning, not a literal translation)
Narrated after the Prophet ﷺ saw a man sleeping on his stomach in the mosque and woke him with his foot to say this.
Commentators pair this with the existing 'Sleeping on the Right Side' entry as two halves of the same guidance on sleep posture — one positive instruction, one direct discouragement.