The Messenger of Allah ﷺ used to recite in witr: Glorify the Name of Your Lord, the Most High;' and "Say: O you disbelievers!'; and 'Say: He is Allah, (the) One." And after he had said the salam, he would say: Subhanal-Malikil-Quddus (Glory be to the Sovereign, the Most Holy).
أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يُوتِرُ بِ { سَبِّحِ اسْمَ رَبِّكَ الأَعْلَى } وَ { قُلْ يَا أَيُّهَا الْكَافِرُونَ } وَ { قُلْ هُوَ اللَّهُ أَحَدٌ } وَإِذَا فَرَغَ قَالَ سُبْحَانَ الْمَلِكِ الْقُدُّوسِ أَرْسَلَهُ هِشَامٌ