'Foolishness' in the Bible

A prudent man concealeth knowledge; But the heart of fools proclaimeth foolishness.

The foolishness of man subverteth his way; And his heart fretteth against Jehovah.

Foolishness is bound up in the heart of a child; But the rod of correction shall drive it far from him.

The thought of foolishness is sin; And the scoffer is an abomination to men.

Though thou shouldest bray a fool in a mortar with a pestle along with bruised grain, Yet will not his foolishness depart from him.