Sunan Abi Dawud 1430
سنن أبي داود#1430SahihNarrated Ubayy ibn Ka'b: When the Messenger of Allah (ﷺ) offered salutation in the witr prayer, he said: Glorify be to the king most holy
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Zubair Ali ZaiSahih
In-book reference: 8:15