He that hath a froward heart, whose heart is not plain and upright, but false towards God or men, findeth no good; shall not get that advantage by his dissimulation which he intends and expects, but shall fall into mischief, as is implied from the opposite clause. He that hath a perverse tongue; that speaks deceitfully or wickedly. So here is a comparison between an evil heart and an evil tongue, and, the ill effects of both of them.
Related Commentaries of Proverbs 17:20
Proverbs 17:20
20 He that hath a frowardh heart findeth no good: and he that hath a perverse tongue falleth into mischief.