Jamieson, Fausset and Brown on Ecclesiastes 4:14

14. out of prison--Solomon uses this phrase of a supposed case; for example, Joseph raised from a dungeon to be lord of Egypt. His words are at the same time so framed by the Holy Ghost that they answer virtually to Jeroboam, who fled to escape a "prison" and death from Solomon, to Shishak of Egypt (1Ki 11:40). This unconscious presaging of his own doom, and that of Rehoboam, constitutes the irony. David's elevation from poverty and exile, under Saul (which may have been before Solomon's mind), had so far their counterpart in that of Jeroboam.

whereas ... becometh poor--rather, "though he (the youth) was born poor in his kingdom" (in the land where afterwards he was to reign).