It is reported on the authority of 'A'isha that the prayer of Messenger of Allah ﷺ in the night consisted of ten rak'ahs. He observed a Witr and two rak'ahs (of Sunan) of the dawn prayer, and thus the total comes to thirteen rak'ahs.
سَمِعْتُ عَائِشَةَ تَقُولُ كَانَتْ صَلاَةُ رَسُولِ اللَّهِ ﷺ مِنَ اللَّيْلِ عَشَرَ رَكَعَاتٍ وَيُوتِرُ بِسَجْدَةٍ وَيَرْكَعُ رَكْعَتَىِ الْفَجْرِ فَتِلْكَ ثَلاَثَ عَشْرَةَ رَكْعَةً