question #2 Sahih al-Bukhari 6431, Book 81, Hadith 20 : How does the accumulation of wealth relate to the concept of reward in the afterlife according to this narration?

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).