Solomon
Ecclesiastes 7:25BSB·traditional attribution

I directed my mind to understand, to explore, to search out wisdom and explanations, and to understand the stupidity of wickedness and the folly of madness.

Matthew Henry Presbyterian @wholebiblehenry

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

John Gill Reformed Baptist @doctorgill

I applied mine heart to know, and to search, and to seek out wisdom,.... Or, "I and my heart turned about" (h); took a circuit, a tour throughout the whole compass of things; looked into every corner, and went through the circle of knowledge, in order to search and find out what true wisdom is; which is no other than Christ, and a spiritual knowledge...

Jamieson-Fausset-Brown Reformed @jfbcommentary

Literally, "I turned myself and mine heart to." A phrase peculiar to Ecclesiastes, and appropriate to the penitent turning back to commune with his heart on his past life. wickedness of folly--He is now a step further on the path of penitence than in Ecc 1:17; Ecc 2:12, where "folly" is put without "wickedness" prefixed. reason--rather, "the right estimation" of things.