[18:2] 1 sn This expression forms an understatement (tapeinosis); the opposite is the point – he detests understanding or discernment.
[18:2] 2 tn The Hitpael infinitive construct בְּהִתְגַּלּוֹת (bÿhitgalot) functions nominally as the object of the preposition. The term means “reveal, uncover, betray.” So the fool takes pleasure “in uncovering” his heart.
[18:2] 3 tn Heb “his heart.” This is a metonymy meaning “what is on his mind” (cf. NAB “displaying what he thinks”; NRSV “expressing personal opinion”). This kind of person is in love with his own ideas and enjoys spewing them out (W. McKane, Proverbs [OTL], 515). It is the kind of person who would ask a question, not to learn, but to show everyone how clever he is (cf. TEV).