‘Rejoice, O young man, in your youth, and let your heart cheer you in the days of your youth, and walk in the ways of your heart and in the sight of your eyes. But know that for all these things God will bring you into judgment. Therefore remove causes of sorrow from your heart, and put away evil from your flesh. For youth and the prime of life are vanity. Remember also your creator in the days of your youth, before the evil days come, and the years draw near when you will say I have no pleasure in them.'
The young men are told to enjoy the fact that they are young, and their lives while they are yet young, and make the most of their youth, doing the things that they desire, but to remember that for how they behave they will be brought into judgment. Thus they must remove from their lives anything that will cause distress and sorrow to others, and not give way to the evils of the flesh.
But they must remember that youth and the prime of life are soon over (they are ‘vanity'). Or that they are futile and vain. Thus they must consider their ways and not over-exalt themselves.
‘Prime of life.' Alternately the word possibly means ‘black hair', and thus the period before they become grey-headed.
Consequently they must in their youth remember their Creator (compare Psalms 100:3; Isaiah 43:15), for it is He Who will call them to account. The thought is that they are to give Him due regard, something that will involve being faithful to Him with regard to the covenant (Deuteronomy 8:18; Deuteronomy 15:15; Psalms 78:35; Psalms 119:55; Numbers 15:40; Jdg 8:34; 1 Chronicles 16:12; Isaiah 46:9; compare the use in Exodus 20:8; Exodus 32:13; Leviticus 26:42; Leviticus 26:45). Each will have to answer for what he is and does.
They are reminded that they will one day grow old, and the evil days will come, the days of weakness and failing faculties, the days when life becomes more of a burden than a pleasure. Thus they must enjoy youth while they may, and make the most of the oportunities that it offers, always; however, remembering that God will be their Judge..