In normal language the word “manifest” simply means to make something clear or obvious. A unique use, in fact, has to do with shipping; a ship’s manifest is a list of all the people and goods on board, making it clear what belongs there and what does not.
It’s interesting, though, that in the Bible the word “manifest” appears only in the New Testament, and – in the Gospels particularly – is generally connected with the Lord.
Swedenborg says that to “manifest” something or make something manifest means to reveal the deepest true ideas about the Lord in the Bible, and is something that happens particularly in the process of bringing one church to an end and beginning another. This is, of course, what the Lord was doing during his life in this world; by revealing new and deeper truths, he was bringing an end to the Jewish faith as the conduit for truth to the world and launching its successor, the Christian church.
Passages from Swedenborg
Apocalypse Revealed (Rogers) n. 668
668. “For Your judgments have been manifested.” This symbolically means that the truths in the Word openly attest to this.
Judgments symbolize the Divine truths in accordance with which a person is to live, truths which reveal his character and are the precepts against which he will be judged. Moreover, because these Divine truths are found in the Word, and the Word now lies open, testifying that the Lord alone is God of heaven and earth, therefore the declaration that “Your judgments have been manifested” means symbolically that the truths in the Word attest to this.
That the Word now lies open, testifying that the Lord alone is God of heaven and earth, that a person ought to live in accordance with His precepts, and that today’s faith is to be rejected, can be seen from four doctrinal works now published, one being The Doctrine of the New Jerusalem Regarding the Lord, another The Doctrine of the New Jerusalem Regarding the Sacred Scripture, a third The Doctrine of Life for the New Jerusalem, and fourth The Doctrine of the New Jerusalem Regarding Faith. These are the doctrines meant by the declaration, “For Your judgments have been manifested.”
Apocalypse Explained (Tansley) n. 946
946. Because thy judgments have been made manifest. That this signifies that Divine truths are revealed to them, is evident from the signification of judgments, as denoting Divine truths, of which we shall speak presently; and from the signification of being manifested, as denoting to be revealed. That Divine truths are revealed at the end of the church, and that they have been revealed, will be shown in what follows in this chapter, because the subject there treated of is concerning them.