"Between the time when he finished 'Isha' prayer and Fajr, the Prophet ﷺ used to pray eleven Rak'ahs, saying the Taslim after each two Rak'ahs, then praying Witr as one Rak'ah. He would prostrate for as long as it takes one of you to recite fifty verses, then he would raise his head. When the Mu'adhdhin finished the call to Fajr prayer and he could see the dawn, he would pray two brief Rak'ahs, then he would go out with him." Some of these narrators (Ibn Abi Dhi'b, Yunus and 'Amr bin Al-Harith) added some phrases not mentioned by the others in the Hadith. (Using translation from Nasāʾī 685)  

كَانَ رَسُولُ اللهِ ﷺ «يُصَلِّي فِيمَا أَنْ يَفْرُغَ مِنْ صَلَاةِ الْعِشَاءِ إِلَى الْفَجْرِ إِحْدَى عَشْرَةَ رَكْعَةً يُسَلِّمُ مِنْ كُلِّ رَكْعَتَيْنِ ثُمَّ يُوتِرُ بِوَاحِدَةٍ وَيَسْجُدُ سَجْدَةً قَدْرَ مَا يَقْرَأُ أَحَدُكُمْ خَمْسِينَ آيَةً قَبْلَ أَنْ يَرْفَعَ رَأْسَهُ فَإِذَا سَكَتَ الْمُؤَذِّنُ مِنْ صَلَاةِ الْفَجْرِ وَتَبَيَّنَ لَهُ الْفَجْرُ قَامَ فَرَكَعَ رَكْعَتَيْنِ خَفِيفَتَيْنِ ثُمَّ اضْطَجَعَ عَلَى شِقِّهِ الْأَيْمَنِ حَتَّى يَأْتِيَهُ الْمُؤَذِّنُ لِلْإِقَامَةِ فَيَخْرُجَ مَعَهُمْ» وَبَعْضُهُمْ يَزِيدُ عَلَى بَعْضٍ فِي قِصَّةِ الْحَدِيثِ  

"I asked Ibn 'Abbas: 'How did the Messenger of Allah ﷺ pray at night?' He said: 'He prayed eleven Rak'ahs including Witr, then he slept deeply until I could hear him snoring, then Bilal came to him and said: "The prayer, O Messenger of Allah!" Then he got up and prayed two brief Rak'ahs then led the people in prayer, and he did not perform Wudu'.'" (Using translation from Nasāʾī 686)  

أَخْبَرَهُ قَالَ سَأَلْتُ ابْنَ عَبَّاسٍ قُلْتُ كَيْفَ كَانَتْ صَلَاةُ رَسُولِ اللهِ ﷺ بِاللَّيْلِ؟ فَوَصَفَ أَنَّهُ «صَلَّى إِحْدَى عَشْرَةَ رَكْعَةً بِالْوِتْرِ ثُمَّ نَامَ حَتَّى اسْتَثْقَلَ فَرَأَيْتُهُ يَنْفُخُ» فَأَتَاهُ بِلَالٌ فَقَالَ الصَّلَاةَ يَا رَسُولَ اللهِ «فَقَامَ فَصَلَّى رَكْعَتَيْنِ وَصَلَّى لِلنَّاسِ وَلَمْ يَتَوَضَّأْ»