Sahih al-Bukhari 6681
صحيح البخاري#6681SahihNarrated Al-Musaiyab:When the death of Abu Talib approached, Allah's Messenger (ﷺ) came to him and said, "Say: La ilaha illallah, a word with which I will be able to defend you before Allah
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: 83:58