Sunan of Abu Dawood Book 8, Hadith 1466

حَدَّثَنَا يَزِيدُ بْنُ خَالِدِ بْنِ مَوْهَبٍ الرَّمْلِيُّ، حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ أَبِي مُلَيْكَةَ، عَنْ يَعْلَى بْنِ مَمْلَكٍ، أَنَّهُ سَأَلَ أُمَّ سَلَمَةَ عَنْ قِرَاءَةِ، رَسُولِ اللَّهِ صلى الله عليه وسلم وَصَلاَتِهِ فَقَالَتْ وَمَا لَكُمْ وَصَلاَتَهُ كَانَ يُصَلِّي وَيَنَامُ قَدْرَ مَا صَلَّى ثُمَّ يُصَلِّي قَدْرَ مَا نَامَ ثُمَّ يَنَامُ قَدْرَ مَا صَلَّى حَتَّى يُصْبِحَ وَنَعَتَتْ قِرَاءَتَهُ فَإِذَا هِيَ تَنْعَتُ قِرَاءَتَهُ حَرْفًا حَرْفًا ‏.‏

Narrated Umm Salamah, Ummul Mu'minin: Ya'la ibn Mumallak said that he asked Umm Salamah about the recitation and prayer of the Messenger of Allah (ﷺ). She said: What have you to do with his prayer? He would pray, then sleep as long as he had prayed, till morning. She then described his recitation and did so with an exposition word by word