Sahih al-Bukhari 1464
صحيح البخاري#1464SahihNarrated Abu Huraira:The Prophet (ﷺ) said, "There is no Zakat either on a slave or on a horse belonging to a Muslim
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: 24:66