Proverbs 17:20

He that hath a froward heart findeth no good: and he that hath a perverse tongue falleth into mischief.

He that hath a froward heart findeth no good - one whose "heart is deep" (); one "with a double heart" (). The opposite to an open, sincere, upright heart ().

And he that hath a perverse (crafty) tongue falleth into mischief - a tongue adapting itself to those with whom it converses; not only discrepant from the heart, but from itself. "Double-tongued" (; James 3:9). The perverse think, by the subtlety which twists itself into all shapes, to 'find good' and escape "mischief." But the reverse ensues: it "findeth no good," and "falleth into mischief."