Ecclesiastes 3:9 - Joseph Benson’s Commentary on the Old and New Testaments

What profit hath he that worketh, &c. Seeing then all events are out of man's power, and no man can do or enjoy any thing at his pleasure, but only when God pleaseth, as has been shown in many particulars, and is as true and certain in all others, hence it follows that all men's labours, without God's blessing, are unprofitable, and utterly insufficient to make them happy.