Mishkat al-Masabih 1274, 1275

Ubayy b. Ka'b said that when God’s Messenger gave the salutation in the witr he said, “Glory be to the King most holy.” Abu Dawud and Nasa’i transmitted it, Nasa’i adding that he said it three times, prolonging the words. In a version by Nasa’i from ‘Abd ar-Rahman b. Abza from his father, he said that he used to say three times when he uttered that salutation, “Glory be to the King most holy”, raising his voice when saying it the third time.