Sahih Muslim 2766
صحيح مسلم#2766SahihIbn Umar (Allah be pleased with them) reported Allah's Messenger (ﷺ) as saying:He who is anxious to seek it (Lailat-ul-Qadr) should seek it in the last ten (nights of Ramadan)
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: 13:272