Sahih al-Bukhari 3958
صحيح البخاري#3958SahihNarrated Al-Bara:We, the Companions of Muhammad used to say that the number of the warriors of Badr was the same as the number of Saul's companions who crossed the river (of Jordan) with him, and none crossed the river with him but a believer, and they were over three-hundred-and-ten men
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: 64:10