Sahih al-Bukhari 6748
صحيح البخاري#6748SahihNarrated Ibn `Umar:A man and his wife had a case of Lian (or Mula'ana) during the lifetime of the Prophet (ﷺ) and the man denied the paternity of her child. The Prophet (ﷺ) gave his verdict for their separation (divorce) and then the child was regarded as belonging to the wife only
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 85:25