Exactly where [in the OT prophecy] the attempt at literal description ends and symbolism begins, the writers themselves probably did not know, and we can hardly guess. But we shall be wise to treat the entire scheme of imagery as language appropriate to describe that which lies upon the frontier of normal experience, which therefore cannot be directly communicated in plain speech. But the prophets seriously believed that what they spoke of (in however cryptic terms) would happen. The early Christians believed it had happened
According to the Scriptures, 73.