They are created now, and not from the beginning
Not that they were now done or brought into being, for as yet Cyrus was not born; though the raising of him up, and holding his right hand, and his executing the counsel of God, are spoken of as if they were already done, because of the certainty of them, ( Isaiah 45:1 Isaiah 45:12 ) ( 46:11 ) . Aben Ezra interprets "created" by "decreed"; though these were not now decreed by God; for no new decrees are made by him; but those which were made by him of old were now revealed and made manifest by prophecy, which is the sense of the phrase; so Kimchi observes,
``the time when they went out of the mouth of God is the time of their creation.''Thus in like manner the incarnation of Christ, his sufferings and death, and salvation by him, things decreed from eternity, are spoken of in this prophecy as if actually done, because of the clear manifestation and certainty of them: even before the day when thou heardest them not;
they were in the breast of God, kept and reserved in his mind, and therefore are before called hidden things, before the Israelites heard anything of them; as were the things respecting Christ, and salvation by him; which were not only in God, who created all things by Christ, but were revealed before the Israelites had any knowledge of them, even to Adam and Eve, immediately after their fall; and were spoken of by all the holy prophets from the beginning of the world: lest thou shouldest say, behold, I knew them;
lest they should ascribe their present knowledge of them to their own sagacity and penetration; as if they were not obliged to a divine revelation, but of themselves had got the secret, and became acquainted with these things.