Sahih al-Bukhari 6431
صحيح البخاري#6431SahihNarrated Qais:I came to Khabbab while he was building a wall, and he (Khabbab) said, "Our companions who have left this world, did not enjoy anything of their reward therein, while we have collected after them, much wealth that we cannot spend but on earth (i.e., on building)
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: 81:20