[Machine] The Messenger of Allah ﷺ used to perform the Witr prayer in three units, in which he would recite Surah Al-Ala (Glorify the name of your Lord, the Most High), Surah Al-Kafirun (Say: O disbelievers), and Surah Al-Ikhlas (Say: He is Allah, the One). He would also engage in supplication before the Ruku' (bowing) position and say "Subhanal-Malikil-Quddus" (Glory be to the Sovereign, the Most Holy) twice, quietly the first time and aloud the second time, extending his voice with it.
كَانَ رَسُولُ اللهِ ﷺ يُوتِرُ بِثَلَاثٍ يَقْرَأُ فِيهَا بِسَبِّحِ اسْمَ رَبِّكَ الْأَعْلَى وَقُلْ يَا أَيُّهَا الْكَافِرُونَ وَقُلْ هُوَ اللهُ أَحَدٌ وَكَانَ يَقْنُتُ قَبْلَ الرُّكُوعِ وَكَانَ يَقُولُ إِذَا سَلَّمَ سُبْحَانَ الْمَلِكِ الْقُدُّوسِ مَرَّتَيْنِ يُسِرُّ بِهِمَا وَالثَّالِثَةُ يَجْهَرُ بِهَا وَيَمُدُّ بِهَا صَوْتَهُ