“Who is considered a rich man? One who is satisfied with what he has, as it is written (Tehillim 128): “When you eat from the work of your hands you will be fortunate and it will be well with you” – fortunate in this world and well with you in the World-to-Come.” — Ben Zoma (Avot 4:1)
The truly rich man is not frantic in his efforts to acquire wealth. Therefore he can dedicate himself constantly to spiritual matters. As a result he will be blessed in both worlds.
“One who is content to enjoy the work of his own hands is greater than one who fears Heaven” say Chazal (Berachot 8a), because King David promises the former that “it will be well with you”, while the latter is merely described as being “fortunate”.
This comparison comes from Ben Zoma. Even if a man is G-d fearing, so long as he lacks the capacity to be content with what he has and frantically pursues wealth he will not be able to properly devote himself to the service of G-d.
- Tosefot Yom Tov