Sunan an-Nasa'i 1749
سنن النسائي#1749Sahihأَخْبَرَنَا يُوسُفُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا حَجَّاجٌ، قَالَ حَدَّثَنَا لَيْثٌ، قَالَ حَدَّثَنِي عُقَيْلٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي إِحْدَى عَشْرَةَ رَكْعَةً فِيمَا بَيْنَ أَنْ يَفْرُغَ مِنْ صَلاَةِ الْعِشَاءِ إِلَى الْفَجْرِ بِاللَّيْلِ سِوَى رَكْعَتَىِ الْفَجْرِ وَيَسْجُدُ قَدْرَ مَا يَقْرَأُ أَحَدُكُمْ خَمْسِينَ آيَةً .
It was narrated that Aishah said:"The Messenger of Allah (ﷺ) used to pray eleven rak'ahs at night between finishing Isha' prayer and Fajr, apart from the two rak'ahs of Fajr, and he would prostrate for as long as it takes one of you to recite fifty verses
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 20:152