The Messenger of Allah ﷺ used to observe thirteen rak'ahs of the night prayer. Five out of them consisted of Witr, and he did not sit, but at the end (for salutation).
كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي مِنَ اللَّيْلِ ثَلاَثَ عَشْرَةَ رَكْعَةً يُوتِرُ مِنْ ذَلِكَ بِخَمْسٍ لاَ يَجْلِسُ فِي شَىْءٍ إِلاَّ فِي آخِرِهَا