The Messenger of Allah ﷺ used to pray thirteen rak'ahs during the night, observing a witr out of that with five, he did not sit during the five except the last and then gave the salutation. Abu Dawud said: Ibn Numair reported it from Hisham recently. (Using translation from Abū Dāʾūd 1338)
«أَنَّ رَسُولَ اللَّهِ ﷺ كَانَتْ صَلَاتُهُ مِنَ اللَّيْلِ ثَلَاثَ عَشْرَةَ رَكْعَةً يُوتِرُ مِنْهَا بِخَمْسٍ لَا يَجْلِسُ فِي شَيْءٍ مِنَ الْخَمْسِ حَتَّى يَجْلِسَ فِي الْآخِرَةِ فَيُسَلِّمَ»