Sunan an-Nasa'i, Volume 2, Book 20, Hadith 1734 (DarusSalam) ⓘ
Khalid said: "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 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."
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، قَالَ أَخْبَرَنِي سَلَمَةُ، وَزُبَيْدٌ، عَنْ ذَرٍّ، عَنِ ابْنِ عَبْدِ الرَّحْمَنِ بْنِ أَبْزَى، عَنْ عَبْدِ الرَّحْمَنِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَقْرَأُ فِي الْوَتْرِ بِـ { سَبِّحِ اسْمَ رَبِّكَ الأَعْلَى } وَ { قُلْ يَا أَيُّهَا الْكَافِرُونَ } وَ { قُلْ هُوَ اللَّهُ أَحَدٌ } ثُمَّ يَقُولُ إِذَا سَلَّمَ " سُبْحَانَ الْمَلِكِ الْقُدُّوسِ " . وَيَرْفَعُ بِـ " سُبْحَانَ الْمَلِكِ الْقُدُّوسِ " . صَوْتَهُ بِالثَّالِثَةِ . رَوَاهُ مَنْصُورٌ عَنْ سَلَمَةَ بْنِ كُهَيْلٍ وَلَمْ يَذْكُرْ ذَرًّا .
also referenced under: Hadith 1733 (Reference) & Book 20, Hadith 136 (In-Book)