"The Messenger of Allah ﷺ used to pray witr with five and seven rak'ahs which he did not separate with any taslim nor talk."  

كَانَ رَسُولُ اللَّهِ ﷺ يُوتِرُ بِخَمْسٍ وَبِسَبْعٍ لاَ يَفْصِلُ بَيْنَهَا بِسَلاَمٍ وَلاَ بِكَلاَمٍ  

"The Messenger of Allah ﷺ used to pray witr with seven or five (rak'ahs), not separating between them with the taslim."  

كَانَ رَسُولُ اللَّهِ ﷺ يُوتِرُ بِسَبْعٍ أَوْ بِخَمْسٍ وَلاَ يَفْصِلُ بَيْنَهُنَّ بِتَسْلِيمٍ  

"Witr is seven and no less than five." I mentioned that to Ibrahim and he said: "From whom did he quote that?" I said: "I do not know." Al-Hakam said: "Then I performed Hajj and I met Miqsam and said to him: 'From whom (did you narrate that)?' He said: 'From the trustworthy one, from Aishah and from Maimunah.'"  

الْوَتْرُ سَبْعٌ فَلاَ أَقَلَّ مِنْ خَمْسٍ فَذَكَرْتُ ذَلِكَ لإِبْرَاهِيمَ فَقَالَ عَمَّنْ ذَكَرَهُ قُلْتُ لاَ أَدْرِي قَالَ الْحَكَمُ فَحَجَجْتُ فَلَقِيتُ مِقْسَمًا فَقُلْتُ لَهُ عَمَّنْ قَالَ عَنِ الثِّقَةِ عَنْ عَائِشَةَ وَعَنْ مَيْمُونَةَ  

The Prophet ﷺ used to pray witr with five and he did not sit except in the last (rak'ah) of them.  

أَنَّ النَّبِيَّ ﷺ كَانَ يُوتِرُ بِخَمْسٍ وَلاَ يَجْلِسُ إِلاَّ فِي آخِرِهِنَّ