Sunan An-Nasa'i

It was narrated 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 after he had said the salam, he would say: Subhanal-Malikil-Quddus (Glory be to the Sovereign, the Most Holy) raising his voice the third time