Jamieson, Fausset and Brown on Ecclesiastes 8:14

14. An objection is here started (entertained by Solomon in his apostasy), as in Ec 3:16; 7:15, to the truth of retributive justice, from the fact of the just and the wicked not now receiving always according to their respective deserts; a cavil, which would seem the more weighty to men living under the Mosaic covenant of temporal sanctions. The objector adds, as Solomon had said, that the worldling's pursuits are "vanity" (Ec 8:10), "I say (not 'said') this also is vanity. Then I commend mirth," &c. [Holden]. Ec 8:14, 15 may, however, be explained as teaching a cheerful, thankful use of God's gifts "under the sun," that is, not making them the chief good, as sensualists do, which Ec 2:2; 7:2, forbid; but in "the fear of God," as Ec 3:12; 5:18; 7:18; 9:7, opposed to the abstinence of the self-righteous ascetic (Ec 7:16), and of the miser (Ec 5:17).