Ecclesiastes 2:21-23

New Catholic Bible

²¹ For even though a man may labor with wisdom and knowledge and skill, he must leave everything he has to be enjoyed by another who has not toiled for it in any way. This also is vanity and a great misfortune.

²² For what does a man gain from all the toil and effort that he has expended under the sun? ²³ His days are filled with pain and his labors are filled with stress. Even at night he has no peace of mind. This also is vanity.