Sahih al-Bukhari 2487
صحيح البخاري#2487SahihNarrated Anas:that Abu Bakr As-Siddiq wrote to him the law of Zakat which was made obligatory by Allah's Apostle. He wrote: 'Partners possessing joint property (sheep) have to pay its Zakat equally
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: 47:5