The Prophet ﷺ used to pray thirteen rak'ahs during the night including the two rak'ahs of the dawn prayer.  

أَنَّ النَّبِيَّ ﷺ كَانَ يُصَلِّي بِاللَّيْلِ ثَلاَثَ عَشْرَةَ رَكْعَةً بِرَكْعَتَىِ الْفَجْرِ  

"The Messenger of Allah used to pray in the night (Qiyamul-Lail) two Rak'ah by two, then when he finished he would use the tooth stick."  

كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي بِاللَّيْلِ رَكْعَتَيْنِ رَكْعَتَيْنِ ثُمَّ يَنْصَرِفُ فَيَسْتَاكُ  

[Machine] The translation of the given text into English is: The Messenger of Allah ﷺ used to pray eight rak'ahs (units of prayer) at night, then he would add three rak'ahs for Witr prayer, and he would also pray two rak'ahs of Fajr prayer.  

كَانَ رَسُولُ اللهِ ﷺ يُصَلِّي بِاللَّيْلِ ثَمَانِيَ رَكَعَاتٍ وَيُوتِرُ بِثَلاثٍ وَيُصَلِّ رَكْعَتَيِ الْفَجْرِ