In the Bible, there is a writing style often called “apocalyptic.” Apocalyptic writers use signs, symbols, numbers, and patterns to teach on different levels. The book of Revelation is a classic example of apocalyptic writing.
Many prophets write with images, signs, and symbols. These passages often have multiple meanings. For example, Isaiah 7.14 says a virgin will conceive and call her son’s name Immanuel. Judah was in the middle of violent warfare and needed reassurance God would keep his promises. The sign would be powerless if nothing happened until 730 years later when Jesus was born. Isaiah intended for this prophecy and sign to happen sometime soon, probably within a few years.