Isaiah 55 – Thoughts – intentions; they are not synonymous; they are 2 different things.

Isa 55:7
Let the wicked forsake his way, And the unrighteous man his thoughts; And let him return to the LORD, And He will have compassion on him; And to our God, For He will abundantly pardon.

Let the wicked forsake his way and the unrighteous man his "thoughts." "Thoughts" is the Hebrew word H4284. machashabah, makh-ash-aw-baw'; or machashebeth, makh-ash-eh'-beth; from H2803; a contrivance, i.e. (concr.) a texture, machine, or (abstr.) intention, plan (whether bad, a plot; or good, advice):--cunning (work), curious work, device (-sed), imagination, invented, means, purpose, thought. The passage says "Let the unrighteous man forsake his "intentions." The Spirit of Elohim within us makes our intentions to be His will. Elohim will have compassion on him and will abundantly pardon (forgive) him. Pardon - H5545. calach, saw-lakh'; a prim. root; to forgive:--forgive, pardon, spare.
Elohim will abundantly forgive those who forsake their wicked ways and evil intentions.
Isa 1:16-20 “Wash yourselves, make yourselves clean; Remove the evil of your deeds from My sight. Cease to do evil, 17Learn to do good; Seek justice, Reprove the ruthless; Defend the orphan, Plead for the widow. “Let Us Reason” 18“Come now, and let us reason together,” Says the LORD, “Though your sins are as scarlet, They will be as white as snow; Though they are red like crimson, They will be like wool. 19“If you consent and obey, You will eat the best of the land; 20“But if you refuse and rebel, You will be devoured by the sword.” Truly, the mouth of the LORD has spoken.
Jer. 4:14 Wash your heart from evil, O Jerusalem, That you may be saved. How long will your wicked thoughts Lodge within you?
2 Chron 7:14 and My people who are called by My name humble themselves and pray, and seek My face and turn from their wicked ways, then I will hear from heaven, will forgive their sin, and will heal their land.
Prov. 28:13 He who conceals his transgressions will not prosper, But he who confesses and forsakes them will find compassion.
Ezek. 18:21-23 “But if the wicked man turns from all his sins which he has committed and observes all My statutes and practices justice and righteousness, he shall surely live; he shall not die. 22“All his transgressions which he has committed will not be remembered against him; because of his righteousness which he has practiced, he will live. 23“Do I have any pleasure in the death of the wicked,” declares the Lord GOD, “rather than that he should turn from his ways and live?
Ezek. 33:11 “Say to them, ‘As I live!’ declares the Lord GOD, ‘I take no pleasure in the death of the wicked, but rather that the wicked turn from his way and live. Turn back, turn back from your evil ways! Why then will you die, O house of Israel?’
Hosea 14:1-2 Return, O Israel, to the LORD your God, For you have stumbled because of your iniquity. 2Take words with you and return to the LORD. Say to Him, “Take away all iniquity, And receive us graciously, That we may present the fruit of our lips.
Isa 55:8
"For My thoughts are not your thoughts, Neither are your ways My ways," declares the LORD.
Isa 55:9
"For as the heavens are higher than the earth, So are My ways higher than your ways, And My thoughts than your thoughts.

His thoughts are not man's thoughts and His ways are not man's ways.
Psalm 36:5-10 Thy lovingkindness, O LORD, extends to the heavens, Thy faithfulness reaches to the skies. 6Thy righteousness is like the mountains of God; Thy judgments are like a great deep. O LORD, Thou preservest man and beast. 7How precious is Thy lovingkindness, O God! And the children of men take refuge in the shadow of Thy wings. 8They drink their fill of the abundance of Thy house; And Thou dost give them to drink of the river of Thy delights. 9For with Thee is the fountain of life; In Thy light we see light. 10O continue Thy lovingkindness to those who know Thee, And Thy righteousness to the upright in heart.
Psalm 103:10-12 He has not dealt with us according to our sins, Nor rewarded us according to our iniquities. 11For as high as the heavens are above the earth, So great is His lovingkindness toward those who fear Him. 12As far as the east is from the west, So far has He removed our transgressions from us. His ways are grace and Truth.

Psalm 25:10 All the paths of the LORD are lovingkindness and truth To those who keep His covenant and His testimonies.
Isa 55:10
"For as the rain and the snow come down from heaven, And do not return there without watering the earth, And making it bear and sprout, And furnishing seed to the sower and bread to the eater;
Isa 55:11
So shall My word be which goes forth from My mouth; It shall not return to Me empty, Without accomplishing what I desire, And without succeeding in the matter for which I sent it.

The Word of Elohim will not return empty. It will accomplish His purpose.
1 Thess. 2:13 And for this reason we also constantly thank God that when you received from us the word of God’s message, you accepted it not as the word of men, but for what it really is, the word of God, which also performs its work in you who believe.
James 1:18 In the exercise of His will He brought us forth by the word of truth, so that we might be, as it were, the first fruits among His creatures.

1 Peter 1:22-25 Since you have in obedience to the truth purified your souls for a sincere love of the brethren, fervently love one another from the heart, 23for you have been born again not of seed which is perishable but imperishable, that is, through the living and abiding word of God. 24For, “ALL FLESH IS LIKE GRASS, AND ALL ITS GLORY LIKE THE FLOWER OF GRASS. THE GRASS WITHERS, AND THE FLOWER FALLS OFF, 25BUT THE WORD OF THE LORD ABIDES FOREVER.” And this is the word which was preached to you.