Sahih al-Bukhari 4780
صحيح البخاري#4780SahihNarrated Abu Huraira:The Prophet, said, "Allah said, 'I have prepared for My pious worshipers such things as no eye has ever seen, no ear has ever heard of, and nobody has ever thought of. All that is reserved, besides which, all that you have seen, is nothing." Then he recited:-- 'No soul knows what is kept hidden (in reserve) for them of joy as a reward for what they used to do
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: 65:302