Sahih al-Bukhari 6712
صحيح البخاري#6712SahihNarrated Al-Ju'aid bin `Abdur-Rahman:As-Sa'ib bin Yazid said, "The Sa' at the time of the Prophet (ﷺ) was equal to one Mudd plus one-third of a Mudd of your time, and then it was increased in the time of Caliph `Umar bin `Abdul `Aziz
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: 84:5