Riyad as-Salihin
Riyad as-Salihin 821
Manners of Lying down on one's back and placing one leg upon the Other
Arabic hadith text
وعن ابن عمر رضى الله عنهما قال: رأيت رسول الله صلى الله عليه وسلم بفناء الكعبة محتبياً بيديه هكذا. ووصف بيديه الاحتباء، وهو القرفصاء. ((رواه البخاري)).
Translation
Ibn 'Umar (May Allah be pleased with them) reported
I saw Messenger of Allah (ﷺ) sitting in the compound of the Holy Ka'bah, with the thighs against the stomach and arms around his legs.[Al- Bukhari].