He asked Aishah about the prayer of the Messenger of Allah ﷺ at night. She said: "He used to pray thirteen rak'ahs: nine rak'ahs standing, one of which was witr, and two rak'ahs sitting. When he wanted to bow he would stand up, and bow and prostrate, and he did that after witr. Then when he heard the call for Subh, he stood up and prayed two brief rak'ahs. (Using translation from Nasāʾī 1756)  

عَنْ صَلَاةِ رَسُولِ اللهِ ﷺ مِنَ اللَّيْلِ فَقَالَتْ كَانَ «يُصَلِّي مِنَ اللَّيْلِ ثَلَاثَ عَشْرَةَ رَكْعَةً تِسْعَ رَكَعَاتٍ قَائِمًا وَيُوتِرُ فِيهَا وَرَكْعَتَيْنِ جَالِسًا فَإِذَا أَرَادَ أَنْ يَرْكَعَ قَامَ فَرَكَعَ وَسَجَدَ وَيَفْعَلُ ذَلِكَ بَعْدَ الْوِتْرِ فَإِذَا سَمِعَ نِدَاءَ الصُّبْحِ قَامَ فَرَكَعَ رَكْعَتَيْنِ خَفِيفَتَيْنِ»