Sahih Muslim 3762
صحيح مسلم#3762SahihAbu Huraira (Allah be pleased with him) reported that Sa'd b. Ubada (Allah be pleased with him) said:Messenger of Allah, if I were to find with my wife a man, should I wait until I bring four witnesses? He said: Yes
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: 19:20