حَدَّثَنَا ابْنُ الْمُثَنَّى، حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنْ حَنْظَلَةَ، عَنِ الْقَاسِمِ بْنِ مُحَمَّدٍ، عَنْ عَائِشَةَ، قَالَتْ ‏:‏ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي مِنَ اللَّيْلِ عَشْرَ رَكَعَاتٍ، وَيُوتِرُ بِسَجْدَةٍ، وَيَسْجُدُ سَجْدَتَىِ الْفَجْرِ، فَذَلِكَ ثَلاَثَ عَشْرَةَ رَكْعَةً ‏.‏
Translation
Narrated Abdullah ibn Abbas

I spent a night with my maternal aunt Maymunah. The Prophet (ﷺ) got up to pray at night. He prayed thirteen rak'ahs including two rak'ahs of the dawn prayer. I guessed that he stood in every rak'ah as long as one could recite Surah al-Muzzammil (73).