رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 820
The Book of the Etiquette of Sleeping, Lying and Sitting etc
Manners of Lying down on one's back and placing one leg upon the Other
وَعَنْ جَابِرِ بْنِ سَمُرَةٍ رضى اللَّه عَنْهُ قَالَ: كَانَ النَّبِيُّ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ إِذَا صَلَّى الْفَجْرَ تَرَبَّعَ فِي مَجْلِسِهِ حَتَّى تَطْلُعَ الشَّمْسُ حَسْنَاءَ. حَدِيث صَحِيح، رَوَاهُ أَبُو دَاوُد وغيره بأسانيد صحيحة.
Jabir bin Samurah (May Allah be pleased with him) reported: After the Fajr (dawn) prayer the Prophet (ﷺ) used to sit crossed legged in the same place in which he had prayed till the sun shone brightly. [Abu Dawud].
Riyad as-Salihin, 820