"Shu'bah narrated to us, he said: Salamah and Zubaid informed me, from Dharr, from Ibn 'Abdur-Rahman bn Abza from Abdur-Rahman, that 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 when he said the taslim, he would say: Subhanal-Malikil-Quddus (Glory be to the Sovereign, the Most Holy) three times, raising his voice with Subhanal-Malikil-Quddus the third time."
أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَقْرَأُ فِي الْوَتْرِ بِ { سَبِّحِ اسْمَ رَبِّكَ الأَعْلَى } وَ { قُلْ يَا أَيُّهَا الْكَافِرُونَ } وَ { قُلْ هُوَ اللَّهُ أَحَدٌ } ثُمَّ يَقُولُ إِذَا سَلَّمَ سُبْحَانَ الْمَلِكِ الْقُدُّوسِ وَيَرْفَعُ بِ سُبْحَانَ الْمَلِكِ الْقُدُّوسِ صَوْتَهُ بِالثَّالِثَةِ رَوَاهُ مَنْصُورٌ عَنْ سَلَمَةَ بْنِ كُهَيْلٍ وَلَمْ يَذْكُرْ ذَرًّا