Sahih al-Bukhari 2538
صحيح البخاري#2538SahihNarrated Hisham:My father told me that Hakim bin Hizam manumitted one-hundred slaves in the Pre-Islamic period of ignorance and slaughtered one-hundred camels (and distributed them in charity). When he embraced Islam he again slaughtered one-hundred camels and manumitted one-hundred slaves. Hakim said, "I asked Allah's Messenger (ﷺ), 'O Allah's Messenger (ﷺ)! What do you think about some good deeds I used to practice in the Pre-Islamic period of ignorance regarding them as deeds of righteousness?' Allah's Apostle said, "You have embraced Islam along with all those good deeds you did
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: 49:22