Proverbs 19:21 - Ellicott's Commentary On The Whole Bible

There are many devices (or, thoughts) in a man’s heart. — “He disquieteth himself in vain” (Psalms 39:6), endeavouring to carry out his various plans in life, while the one unchangeable “counsel of the Lord,” that shall stand — i.e., abide in all its fulness. (Comp, Isaiah 46:10-11; Psalms 33:11; Job 23:13.)