Ecclesiastes 9:9

Live joyfully with the wife whom thou lovest The absence of the article from the Hebrew noun for "woman" has been wrongly pressed by interpreters who see in the Debater the advocate of sensuality, as indicating indifference to the marriage union ("live joyfully with awoman whom thou lovest, whether wife or not"), and is simply the indefinite form natural to a general maxim. So we should say naturally "live with awife whom you love." The conclusion in which the writer for the present rests is that while sensual indulgence in excess leads to misery and shame, and brings men into contact with the most hateful form of womanhood (chs. Ecclesiastes 2:11; Ecclesiastes 7:26), there is a calm peacefulness in the life of a happy home, which, though it cannot remove the sense of the "vanity" and transitoriness of life, at least makes it endurable. If there is, as some have thought, an undertone of irony, it is one which springs from a sympathy with the joy as well as the sorrow of life, and not that of a morose cynicism, saying, "enjoy … if you can."

all the days of thy vanity The iteration emphasizes the wisdom of making the most of the few days of life. The thought is essentially the same as that expressed in the Carpe diemof Hor. Od.i. 11.

that is thy portion in this life This, the calm regulated enjoyment of the wiser Epicureans.