The Messenger of Allah ﷺ used to pray ten rakahs during the night, then perform witr with a single prostration, and then pray the two rakahs of Fajr, making thirteen rakahs in total.
حدثنا ابن المثنى حدثنا ابن أبي عدي عن حنظلة عن القاسم بن محمد
كان رسول الله ﷺ يصلي من الليل عشر ركعات ويوتر بسجدة ويسجد سجدتي الفجر فذلك ثلاث عشرة ركعة
Bukhari, Tahajjud, chapter "How was the prayer of the Prophet ﷺ?" etc., no. 1140, etc., no. 738, and Muslim, Prayer of the Traveler, chapter "The night prayer and the number of the Prophet's ﷺ rakahs at night," 128, from the hadith of Hanzala.