C. F. Keil and Franz Delitzsch on Ecclesiastes 2:17

Ecc 2:17 “The life became hateful to me; for the work which man accomplsihes under the sun was grievous to me: because all is vain and windy effort.” He hated life; and the labour which is done under the sun, i.e., the efforts of men, including the fate that befalls men, appeared to him to be evil (repugnant). The lxx translate: πονηρὸν επ ̓ ἐμέ; the Venet.: κακὸν ἐπ ̓ ἐμοί; and thus Hitzig: as a woeful burden lying on me. But עלי רע is to be understood after tov al, Est 3:9, etc., cf. Psa 16:6, and as synon. with בּעיני or לפני (cf. Dan. 3:32), according to which Symmachus: κακὸν γάρ μοι ἐφάνη. This al belongs to the more modern usus loq., cf. Ewald, §217 i. The end of the song was also again the grievous ceterum censeo: Vanity, and a labour which has wind as its goal, wind as its fruit.