"Shu'bah narrated to us, from Salamah and Zubaid, from Dharr, from Ibn Abdur-Rahman bin Abza from his father 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 the third time."
Reference: Sunan an-Nasa'i 1732 In-book : Book 20, Hadith 135 English translation : Vol. 2, Book 20, Hadith 1733
Help us gift a modern, ad-free Islamic application for the Muslim Ummah. Your donation will be recorded as Sadaqah Jariyah in your book of deeds, In Sha Allah.