Sahih Muslim 3750
صحيح مسلم#3750SahihSa'id b. Jubair reported:I asked Ibn 'Umar (Allah be pleased with them) about invoking curse (li'an), and he narrated Similarly from Allah's Apostle (ﷺ)
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: 19:8