Isaiah 41:26

Yahweh is the only predictor of Cyrus, and His prediction proves Him unique among the "gods." In Isaiah’s day the pagans claimed that their gods sent them messages, but these messages were vague and not specific. The fulfillment of this prediction would prove that Yahweh was the true God. Many scholars believe that the writer of this part of Isaiah, if not the whole book, lived after Cyrus began his conquests about 545 B.C. If that were so, the whole point of this passage loses its force.