"The night prayer of Messenger of Allah was thirteen Rak'ah, five of which were his Witr, not sitting in any of them except at the end of them. When the Mu'adh-dhin called the Adhan he would stand to perform two light (Rak'ah)."
كَانَتْ صَلاَةُ النَّبِيِّ ﷺ مِنَ اللَّيْلِ ثَلاَثَ عَشْرَةَ رَكْعَةً يُوتِرُ مِنْ ذَلِكَ بِخَمْسٍ لاَ يَجْلِسُ فِي شَيْءٍ مِنْهُنَّ إِلاَّ فِي آخِرِهِنَّ فَإِذَا أَذَّنَ الْمُؤَذِّنُ قَامَ فَصَلَّى رَكْعَتَيْنِ خَفِيفَتَيْنِ قَالَ وَفِي الْبَابِ عَنْ أَبِي أَيُّوبَ
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
"The night prayer of Messenger of Allah was thirteen Rak'ah, five of which were his Witr, not sitting in any of them except at the end of them. When the Mu'adh-dhin called the Adhan he would stand to perform two light (Rak'ah)." (Using translation from Tirmidhī 459)
كَانَتْ صَلَاةُ رَسُولِ اللهِ ﷺ بِاللَّيْلِ ثَلَاثَ عَشْرَةَ رَكْعَةً يُوتِرُ مِنْ ذَلِكَ بِخَمْسٍ لَا يَجْلِسُ فِي شَيْءٍ مِنْهَا إِلَّا فِي آخِرِهَا فَإِذَا أَذَّنَ الْمُؤَذِّنُ قَامَ فَصَلَّى رَكْعَتَيْنِ خَفِيفَتَيْنِ