ENOfficial
‘A’isha said that God’s Messenger used to pray thirteen rak'as during the night, observing a witr out of that with five, and sitting only during the last of them. (Bukhari and Muslim.)
Source: sunnah.com
Other translations
Arabic
وَعَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُصَلِّي مِنَ اللَّيْلِ ثَلَاثَ عَشْرَةَ رَكْعَةً يُوتِرُ مِنْ ذَلِكَ بِخَمْسٍ لَا يَجْلِسُ فِي شَيْء إِلَّا فِي آخرهَا "
sunnah.com