Ecclesiastes 5:16-20

This also is a grievous evil—exactly as he was born, so he shall die. So what advantage has he who labors for the wind? [1 Tim 6:6] All of his life he also eats in darkness [cheerlessly, without sweetness and light], with great frustration, sickness, and anger. Behold, here is what I have seen to be good and fitting: to eat and drink, and to find enjoyment in all the labor in which he labors under the sun during the few days of his life which God gives him—for this is his [allotted] reward. [1 Tim 6:17] Also, every man to whom God has given riches and possessions, He has also given the power and ability to enjoy them and to receive [this as] his [allotted] portion and to rejoice in his labor—this is the gift of God [to him]. For he will not often consider the [troubled] days of his life, because God keeps him occupied and focused on the joy of his heart [and the tranquility of God indwells him].