Sahih Muslim 1785
صحيح مسلم#1785SahihZirr (b. Hubaish) reported:I heard from Ubayy b. Ka'b a statement made by 'Abdullah b. Mas'ud in which he said: He who gets up for prayer (every night) during the year will hit upon Lailat-ul-Qadr. Ubayy said: By Allah I there is no god but He, that (Lailat-ul-Qadr) is in Ramadhan (He swore without reservation: ) By Allah, I know the night; it is the night on which the Messenger of Allah (ﷺ) commanded us to pray. It is that which precedes the morning of twenty-seventy and its indication is that the sun rises bright on that day without rays
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 6:213