Sunan an-Nasa'i #1629 · The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day

Sunan an-Nasa'iIt was narrated from Ya'la bin Mamlak that he asked Umm Salamah
Sunan an-Nasa'i · Book 20 · The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day
Sunan an-Nasa'i · كتاب 20 · كتاب قيام الليل وتطوع النهار
"What do you want to know about his prayer (I.e., you can never match it)? He used to pray, then sleep for as long as he had prayed, then he would pray as long as he had slept, then he would sleep as long as he had prayed, until dawn came." Then she described to him his recitation, and she described a clear recitation in which every letter was distinct
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ عَبْدِ اللَّهِ بْنِ عُبَيْدِ اللَّهِ بْنِ أَبِي مُلَيْكَةَ، عَنْ يَعْلَى بْنِ مَمْلَكٍ، أَنَّهُ سَأَلَ أُمَّ سَلَمَةَ زَوْجَ النَّبِيِّ صلى الله عليه وسلم عَنْ قِرَاءَةِ رَسُولِ اللَّهِ صلى الله عليه وسلم وَعَنْ صَلاَتِهِ فَقَالَتْ مَا لَكُمْ وَصَلاَتَهُ كَانَ يُصَلِّي ثُمَّ يَنَامُ قَدْرَ مَا صَلَّى ثُمَّ يُصَلِّي قَدْرَ مَا نَامَ ثُمَّ يَنَامُ قَدْرَ مَا صَلَّى حَتَّى يُصْبِحَ ‏.‏ ثُمَّ نَعَتَتْ لَهُ قِرَاءَتَهُ فَإِذَا هِيَ تَنْعَتُ قِرَاءَةً مُفَسَّرَةً حَرْفًا حَرْفًا ‏.‏
Reference : Sunan an-Nasa'i 1629In-book reference : Book 20, Hadith 32