النوم على الشق الأيمن
A recommended sleeping posture — lying on the right side after performing ablution — paired with a protective supplication before sleep.
إِذَا أَتَيْتَ مَضْجَعَكَ فَتَوَضَّأْ وُضُوءَكَ لِلصَّلَاةِ، ثُمَّ اضْطَجِعْ عَلَى شِقِّكَ الْأَيْمَنِ
“When you go to your bed, perform ablution as you would for prayer, then lie down on your right side.” (meaning, not a literal translation)
This same narration continues with a specific supplication to say before sleeping, and notes that if death comes during the night, one dies upon the natural disposition (fitra) — tying the physical instruction to a spiritual framing of sleep as a lesser form of death, a theme that recurs across several nighttime practices in the tradition.
Ibn al-Qayyim notes physicians of his era already associated right-side sleeping with easier digestion, since it was thought to position the stomach favorably relative to the liver. He discusses this alongside the broader nightly routine covered in other entries — ablution, dhikr, and posture together forming a single coherent bedtime practice rather than isolated, unrelated instructions.
Some modern research has examined sleep position in relation to digestion and acid reflux, with mixed findings depending on individual anatomy and condition — this remains a less definitively settled area than some other entries on this site, and current medical guidance generally defers to individual comfort and specific diagnosed conditions.