Rejoice, O young man, in thy youth; and let thy heart cheer thee in the days of thy youth, and walk in the ways of thine heart, and in the sight of thine eyes: but know thou, that for all these things God will bring thee into judgment. Rejoice - not advice, but warning. So 1 Kings 22:15 is irony; if thou dost rejoice (carnally, Ecclesiastes 2:2; not moderately, as Ecclesiastes 5:18), etc., then "know thou, that for all these things God will bring thee into judgment" - (Ecclesiastes 3:17; Ecclesiastes 12:14.)
In thy youth-in the days of thy youth - Hengstenberg thinks, distinct Hebrew words х yalduwt (H3208)], adolescence or boyhood, and full-grown youth х bªchuwrowt (H979) literally, the choice age]. This Solomon marks the gradual progress in self-indulgence to which the young especially are prone: they see the roses, but do not discover the thorns, until pierced by them. Religion will cost self-denial, but the want of it infinitely more. Hengstenberg takes the whole literally, and not the first part ironically, as if it were a dissuasion from 'rejoicing.' The parallels (Ecclesiastes 11:8; Ecclesiastes 2:24; Ecclesiastes 3:13; Ecclesiastes 5:18; Ecclesiastes 9:7, favour this. Not excess or self- indulgence, but a cheerful use of God's gifts, as distinguished from a self-righteous, gloomy asceticism, is in this view what is inculcated. Contrast Colossians 2:23. But to "walk in the ways of thine heart, and in the sight of thine eyes" is expressly forbidden in Numbers 15:39; Deuteronomy 29:19. I therefore prefer the former view.