C. F. Keil and Franz Delitzsch on Proverbs 16:22

Pro 16:22 22 A fountain of life is understanding to its possessor;      But the correction of fools is folly.

Oetinger, Bertheau, and others erroneously understand מוּסר of the education which fools bestow upon others; when fools is the subject spoken of, מוּסר is always the education which is bestowed on them, Pro 7:22; Pro 1:7; cf. Pro 5:23; Pro 15:5. Also מוסר does not here mean education, disciplina, in the moral sense (Symmachus, ἔννοια; Jerome, doctrina): that which fools gain from education, from training, is folly, for מוסר is the contrast to מקור חיּים, and has thus the meaning of correction or chastisement, Pro 15:10, Jer 30:14. And that the fruits of understanding (Pro 12:8, cf. שׂכל טוב, fine culture, Pro 13:15) represented by מקור חיים (vid., Pro 10:11) will accrue to the intelligent themselves, is shown not only by the contrast, but also by the expression: Scaturigo vitae est intellectus praeditorum eo, of those (= to those) who are endowed therewith (The lxx well, τοῖς κεκτημένοις). The man of understanding has in this intellectual possession a fountain of strength, a source of guidance, and a counsel which make his life secure, deepen, and adorn it; while, on the contrary, folly punishes itself by folly (cf. to the form, Pro 14:24), for the fool, when he does not come to himself (Psa 107:17-22), recklessly destroys his own prosperity.