"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." (Using translation from Nasāʾī 1714)
كَانَ رَسُولُ اللهِ ﷺ يُوتِرُ بِسَبْعٍ وَبِخَمْسٍ لَا يَفْصِلُ بَيْنَهُنَّ بِسَلَامٍ وَلَا بِكَلَامٍ