Sahih al-Bukhari 530
صحيح البخاري#530SahihNarrated Az-Zuhri that he visited Anas bin Malik at Damascus and found him weeping and asked him why he was weeping. He replied, "I do not know anything which I used to know during the life-time of Allah's Apostle except this prayer which is being lost (not offered as it should be)
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: 9:9