Sunan an-Nasa'i #1650 · The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day

Sunan an-Nasa'iIt was narrated that Aishah said
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
"The Messenger of Allah (ﷺ) used to recite sitting, and when he wanted to bow he would stand up for as long as it takes a person to recite forty verses
أَخْبَرَنَا زِيَادُ بْنُ أَيُّوبَ، قَالَ حَدَّثَنَا ابْنُ عُلَيَّةَ، قَالَ حَدَّثَنَا الْوَلِيدُ بْنُ أَبِي هِشَامٍ، عَنْ أَبِي بَكْرِ بْنِ مُحَمَّدٍ، عَنْ عَمْرَةَ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَقْرَأُ وَهُوَ قَاعِدٌ فَإِذَا أَرَادَ أَنْ يَرْكَعَ قَامَ قَدْرَ مَا يَقْرَأُ إِنْسَانٌ أَرْبَعِينَ آيَةً ‏.‏
Reference : Sunan an-Nasa'i 1650In-book reference : Book 20, Hadith 53