11 When I considered all that I had accomplished[a] and what I had labored to achieve, I found everything to be futile and a pursuit of the wind.[b] There was nothing to be gained under the sun. (Ecclesiastes 2:11 CSB)
Soloman was one of the greatest kings to have ever lived. He pursued every possible aspect of achievement a human can strive for and found it all futile.
Each of these passages conclude with “under the sun” because Soloman knew that the only true value in life was what we do “under the Son”. Those things we do which have an eternal value are the ones which will truly fulfill us.
Yes, we must make a living and tend to our families. But we must do so with Christ love in mind, striving always for not just our advancement in the world but to advance the cause of Christ.
All else is simply vain pursuit.