C. F. Keil and Franz Delitzsch on Proverbs 18:2

Pro 18:2 2 The fool hath no delight in understanding;    But only that his heart may reveal itself therein.

The verb חפץ forms the fut. יחפּץ as well as יחפּץ; first the latter from חפץ, with the primary meaning, to bow, to bend down; then both forms as intransitive, to bend oneself to something, to be inclined to something, Arab. 'ṭf. (Fl.). תּבוּנה is here the intelligence which consists in the understanding of one’s own deficiency, and of that which is necessary to meet it. The inclination of the fool goes not out after such intelligence, but (כּי אם־; according to Ben-Naphtali, כי־אם) only that his heart, i.e., the understanding which he thinks that he already possesses, may reveal itself, show itself publicly. He thinks thereby to show himself in his true greatness, and to render a weighty service to the world. This loquacity of the fool, proceeding from self-satisfaction, without self-knowledge, has already, Pro 12:23, and often, been reprimanded.