He hath said in his heart - The phrase, "he hath said," means that this was his deliberate and settled character. What is here described was no sudden thing. It was not the freak of passion; it was a deliberately-formed purpose. The phrase, "in his heart," means that he had purposed this; he had said this to himself in a spirit of self-gratulation and confidence.
I shall not be moved - That is, he was confident in his present condition, and he apprehended no changes. He had formed his plans so wisely, that he believed he had nothing to apprehend; he feared neither sickness nor adversity; he dreaded not the power of his enemies; he feared nothing even from the providence of God; he supposed that he had laid the foundation for permanent prosperity. This feeling of self-confidence and of security is sometimes found, to an extent that cannot be justified, in the hearts of even good people (compare the note at Job 29:18); and it is common among the wicked. See Psalm 49:11; Job 21:9.
For I shall never be in adversity - Margin, "unto generation and generation." The margin expresses the correct sense. The idea of the wicked, as expressed here, is that they and their families would continue to be prosperous; that a permanent foundation was laid for honor and success, and for transmitting accumulated wealth and honors down to far distant times. It is a common feeling among wicked men that they can make permanent their titles, and possessions, and rank, and that nothing will occur to reduce them to the humble condition of others. Nothing more cleverly shows the pride and atheism of the heart than this; and in nothing are the anticipations and plans of human beings more signally disappointed. Compare the case of Shebna; see the note at Isaiah 22:15 ff.

I shall not be moved - I have whatever I covet. I hold whatsoever I have gotten. I have money and goods to procure me every gratification.

He hath said in his heart, I shall not be moved: for [I shall] (c) never [be] in adversity.
(c) The evil will not touch me, (Isaiah 28:15) or else he speaks thus because he never felt evil.

He hath said in his heart,.... To and within himself, he thought in his own mind; for the thought is the word or speech of the mind, ;
I shall not be moved; from his prosperous and happy condition, abounding: with riches and honours; from his seat of empire, over kings, princes, and the nations of the world; flattering himself that it would never be otherwise with him than it is: even "to generation and generation", I shall not be moved; so the words may be rendered;
for I shall never be in adversity, or "in evil" (d): meaning either the evil of sin; so asserting his innocence, wiping himself clean of all iniquity, claiming to himself the title of "holiness" itself, and the character of infallibility; giving out that he is impeccable, and cannot err; when he is not only almost, but altogether, in all evil; and is , the lawless and wicked one, the man of sin, who is nothing but sin itself. The Targum paraphrases the whole thus; "I shall not be moved from generation to generation from doing evil"; and so it is a boast of impiety, and that none can restrain him from it, no one having a superior power over him; see Psalm 12:4. Or the evil of affliction, or calamity; wherefore we render it "adversity", so Jarchi and Aben Ezra understand it: the note of the former is,
"evil shall not come upon me in my generation,''
or for ever; and the latter compares it with Numbers 11:15; Kimchi and Ben Melech interpret it of long life. It is a vaunt of antichrist, promising himself a continuance of his grandeur, ease, peace, and prosperity; in which he will be wretchedly disappointed. The language and sense are much the same with that of the antichristian Babylon, Revelation 18:7.
(d) "in malo", Montanus, Junius & Tremellius, Piscator, Cocceius, Gejerus; so Ainsworth.

Then in his boundless carnal security he gives free course to his wicked tongue. That which the believer can say by reason of his fellowship with God, בּל־אמּוט (Psalm 30:7; Psalm 16:8), is said by him in godless self-confidence. He looks upon himself in age after age, i.e., in the endless future, as אשׁר לא ברע, i.e., as one who (אשׁר as in Isaiah 8:20) will never be in evil case (ברע as in Exodus 5:19; 2-Samuel 16:8). It might perhaps also be interpreted according to Zac 8:20, Zac 8:23 (vid., Kצhler, in loc.): in all time to come (it will come to pass) that I am not in misfortune. But then the personal pronoun (אני or הוּא) ought not be omitted; whereas with our interpretation it is supplied from אמּוט, and there is no need to supply anything if the clause is taken as an apposition: in all time to come he who.... In connection with such unbounded self-confidence his mouth is full of אלה, cursing, execratio (not perjury, perjurium, a meaning the word never has), מרמות, deceit and craft of every kind, and תּך, oppression, violence. And that which he has under his tongue, and consequently always in readiness for being put forth (Psalm 140:4, cf. Psalm 66:17), is trouble for others, and in itself matured wickedness. Paul has made use of this Psalm 10:7 in his contemplative description of the corruptness of mankind, Romans 3:14.