Proverbs 12:23
A prudent man conceals knowledge: but the heart of fools proclaims foolishness.
Nave's Topical Index—AKJV

Proverbs 22:15
Foolishness is bound in the heart of a child; but the rod of correction shall drive it far from him.
Nave's Topical Index—AKJV

Ecclesiastes 9:3
This is an evil among all things that are done under the sun, that there is one event to all: yes, also the heart of the sons of men is full of evil, and madness is in their heart while they live, and after that they go to the dead.
Nave's Topical Index—AKJV