Sunan An-Nasa'i

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 (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