Contrast the many purposes of man, shifting, changing, from good to better, from bad to worse, and the one unchanging righteous "counsel" of Yahweh.

There are many devices, etc. - The same sentiment as in Proverbs 16:1 (note), where see the note.

[There are] many devices in a (g) man's heart; nevertheless the counsel of the LORD, that shall stand.
(g) Man's device will not have success, unless God governs it, whose purpose is unchangeable.

There are many devices in a man's heart,.... Some about civil things; to get wealth and riches: to obtain honour and glory among men; to attain to a long life, and to perpetuate their memories after death: some about sinful things; to gratify their carnal lusts and sensual appetites; and to do mischief to others, particularly the people of God, and the cause and interest of Christ: some about religious things; coming new doctrines, devising new ordinances and modes of worship; contriving other methods of salvation than by Christ; as by the light of nature; by the law of Moses; by mere morality, civility, and external justice between man and man; by keeping to the religion they were born and brought up in; and by a mere outward profession of religion, and submission to ordinances, and performance of duties, and a multitude more of the like kind;
nevertheless, the counsel of the Lord, that shall stand; and can never be frustrated by the devices of man's heart, though there are many, and that but one; see Psalm 33:10. This may be applied to the Gospel, and the scheme of salvation in it, called the whole counsel of God, Acts 20:27; it being the fruit of infinite wisdom, and the effect of a divine council between the eternal Three, and full of the best advice and instructions to the sons of men; and which has stood, and shall stand, notwithstanding the persecutions of wicked men, the craft of false teachers, and the ridicule of a profane world; it will continue till all the elect are gathered in, even, to the end of the world; and so will the ordinances of it, which are also called the counsel of God, Luke 7:30; and which will continue till the second coming of Christ. Moreover, the purposes of God, his counsels of old, or his eternal decrees, may be here meant; which are wisely formed in his own breast, and are not frustrable; and according to which counsel of his will all things are done in nature, providence, and grace; all things in this world are ordered as he pleases, and all things are done as he has ordered them; all his purposes are or will be fulfilled; his designs will be accomplished in the world and in his church, in spite of all the schemes, contrivances, and opposition of men and devils.

What should we desire, but that all our purposes may agree with God's holy will?

(Compare Proverbs 16:1, Proverbs 16:9; Psalm 33:10-11). The failure of man's devices is implied.

21 Many are the thoughts in a man's heart;
But Jahve's counsel, that stands.
In תּקוּם lies, as at Isaiah 40:8, both: that the counsel of God (His plan of the world and of salvation) is accomplished and comes into actual fact, and that it continues. This counsel is the true reality elevated above the checkered manifoldness of human purposes, aims, and subjectivities, which penetrates and works itself out in history. The thoughts of a man thus gain unity, substance, endurance, only in so far as he subjects himself to this counsel, and makes his thoughts and actions conformable and subordinate to this counsel.