All this I tested by wisdom, saying, “I resolve to be wise.” But it was beyond me.
Solomon had hitherto been proving the vanity of the world and its utter insufficiency to make men happy; now here he comes to show the vileness of sin, and its certain tendency to make men miserable; and this, as the former, he proves from his own experience, and it was a dear-bought experience.
Commenting on Ecclesiastes 7:23-29
All this have I proved by wisdom,.... Referring either to all that he had been discoursing of hitherto in this book, concerning the vanity of natural wisdom and knowledge, of pleasure, power, and riches; or to the several useful instructions given in this chapter, particularly concerning patiently bearing everything from the hands of God or men, Ecc 7:8.
All this--resuming the "all" in Ecc 7:15; Ecc 7:15-22 is therefore the fruit of his dearly bought experience in the days of his "vanity." I will be wise--I tried to "be wise," independently of God. But true wisdom was then "far from him," in spite of his human wisdom, which he retained by God's gift. So "over wise" (Ecc 7:16).