Sahih al-Bukhari 6753
صحيح البخاري#6753SahihNarrated `Abdullah:The Muslims did not free slaves as Sa'iba, but the People of the Pre-Islamic Period of Ignorance used to do so
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: 85:30