Isa 26:3-4 You keep him in perfect peace whose mind is stayed on you, because he trusts in you. Trust in the LORD forever, for the LORD GOD is an everlasting rock.
Isaiah 57:19-21 creating the fruit of the lips. Peace, peace, to the far and to the near,” says the LORD, “and I will heal him. But the wicked are like the tossing sea; for it cannot be quiet, and its waters toss up mire and dirt. There is no peace,” says my God, “for the wicked.”
Psalms 85:7-8 Show us your steadfast love, O LORD, and grant us your salvation. Let me hear what God the LORD will speak, for he will speak peace to his people, to his saints; but let them not turn back to folly.
Micah 5:5 And he shall be their peace.
John 14:27 Peace I leave with you; my peace I give to you. Not as the world gives do I give to you. Let not your hearts be troubled, neither let them be afraid.
John 16:33 I have said these things to you, that in me you may have peace. In the world you will have tribulation. But take heart; I have overcome the world.”
Romans 5:1 Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ.
Ephesians 2:14-16 For he himself is our peace, who has made us both one and has broken down in his flesh the dividing wall of hostility by abolishing the law of commandments expressed in ordinances, that he might create in himself one new man in place of the two, so making peace, and might reconcile us both to God in one body through the cross, thereby killing the hostility.
Philippians 4:7 And the peace of God, which surpasses all understanding, will guard your hearts and your minds in Christ Jesus.
Isaiah 31:1 Woe to those who go down to Egypt for help and rely on horses, who trust in chariots because they are many and in horsemen because they are very strong, but do not look to the Holy One of Israel or consult the LORD!
Psalms 9:10 And those who know your name put their trust in you, for you, O LORD, have not forsaken those who seek you.
Jeremiah 17:7-8 “Blessed is the man who trusts in the LORD, whose trust is the LORD. He is like a tree planted by water, that sends out its roots by the stream, and does not fear when heat comes, for its leaves remain green, and is not anxious in the year of drought, for it does not cease to bear fruit.”
Romans 4:21 fully convinced that God was able to do what he had promised.
That day, seems to mean when the New Testament Babylon shall be levelled with the ground. The unchangeable promise and covenant of the Lord are the walls of the church of God. The gates of this city shall be open. Let sinners then be encouraged to join to the Lord. Thou wilt keep him in peace; in perfect peace, inward peace, outward peace, peace with God, peace of conscience, peace at all times, in all events. Trust in the Lord for that peace, that portion, which will be for ever. Whatever we trust to the world for, it will last only for a moment; but those who trust in God shall not only find in him, but shall receive from him, strength that will carry them to that blessedness which is for ever. Let us then acknowledge him in all our ways, and rely on him in all trials. (Henry)
‘Peace, peace;’ the repetition of the word denoting, as is usual in Hebrew, emphasis, and here evidently meaning undisturbed, perfect peace. That is, the mind that has confidence in God shall not be agitated by the trials to which it shall be subject; by persecution, poverty, sickness, want, or bereavement. (Barnes)
The word “perfect” is not in the Hebrew text, it is there “peace, peace”; which is doubled to denote the certainty of it, the enjoyment of it, and the constancy and continuance of it; and as expressive of all sorts of peace, which God grants unto his people, and keeps for them, and them in; as peace with God and peace with men, peace outward and peace inward, peace here and peace hereafter; and particularly it denotes the abundance of peace that believers will have in the kingdom of Christ in the latter day. (Gill)