Sahih al-Bukhari 5318
صحيح البخاري#5318SahihNarrated Um Salama:(the wife of the Prophet) A lady from Bani Aslam, called Subai'a, become a widow while she was pregnant. Abu As-Sanabil bin Ba'kak demanded her hand in marriage, but she refused to marry him and said, "By Allah, I cannot marry him unless I have completed one of the two prescribed periods." About ten days later (after having delivered her child), she went to the Prophet (ﷺ) and he said (to her), "You can marry now
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: 68:67