24:9

The devising of foolishness is sin,
And the scoffer is an abomination to men.

9:6

Forsake foolishness and live,
And go in the way of understanding.

19:3

The foolishness of a man twists his way,
And his heart frets against the LORD.

15:2

The tongue of the wise uses knowledge rightly,
But the mouth of fools pours forth foolishness.