IBNHIBBAN 2612:
from ʿĀʾishah —
[Machine] The Messenger of Allah ﷺ used to pray eleven rak'ahs between the completion of 'Isha prayer, which is when people are called to the darkness of dawn, and the dawn prayer. In each set of two rak'ahs, he would recite the salaam. Additionally, he would perform one witr rak'ah. When the muezzin finished calling for the dawn prayer and the dawn appeared to him, and the muezzin came to him, he would stand and perform two light rak'ahs, then lie down on his right side until the muezzin came to him with the call to establish the prayer.
ابن حبّان ٢٦١٢:
عن عاءشه —
«كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي فِيمَا بَيْنَ أَنْ يَفْرُغَ مِنْ صَلَاةِ الْعِشَاءِ وَهِيَ الَّتِي يَدْعُو النَّاسُ الْعَتَمَةَ إِلَى الْفَجْرِ إِحْدَى عَشْرَةَ رَكْعَةً يُسَلِّمُ فِي كُلِّ رَكْعَتَيْنِ وَيُوتِرُ بِوَاحِدَةٍ فَإِذَا سَكَتَ الْمُؤَذِّنُ مِنْ صَلَاةِ الْفَجْرِ وَتَبَيَّنَ لَهُ الْفَجْرُ وَجَاءَهُ الْمُؤَذِّنُ قَامَ فَرَكَعَ رَكْعَتَيْنِ خَفِيفَتَيْنِ وَاضْطَجَعَ عَلَى شِقِّهِ الْأَيْمَنِ حَتَّى يَأْتِيَهُ الْمُؤَذِّنُ بِالْإِقَامَةِ»
hadithunlocked.com