A key prophecy can be found in Daniel 9:24-27, which also includes a mystery. First, a prophecy is given regarding the nation of Israel and the appearing of the Messiah with a very specific timeline.

"Seventy weeks have been decreed for your people and your holy city, to finish the transgression, to make an end of sin, to make atonement for iniquity, to bring in everlasting righteousness, to seal up vision and prophecy and to anoint the most holy place. So you are to know and discern that from the issuing of a decree to restore and rebuild Jerusalem until Messiah the Prince there will be seven weeks and sixty-two weeks; it will be built again, with plaza and moat, even in times of distress.“_{[Dn 9:24-25]}

So, first, the Seventy weeks (literally Seventy-Sevens) has to be interpreted as Seventy groups of Seven years – that is, 490 years. Without going into the details, based on other texts and in recognition that a literal 490 weeks is too short a timeframe for these activities, this conclusion can be gleaned.

Note that all the things to be accomplished regarding Israel and Jerusalem has not been accomplished as of yet. But, the scripture does state that the Messiah will appear 483 years after the decree to “restore and rebuild Jerusalem”. The decree did occur and the Messiah did appear according to the timeline! If you want to research further, look into Ezra/Nehemiah and the history books for the decrees and dates. The main thing to note is that Jesus appeared on the scene somewhere within the timetable given.

But, there is still one more week (7 years) to complete the prophecy. In fact, the prophecy says things will occur after the 483 years but before the last 7 years. There is a gap. There is a mystery.

"Then after the sixty-two weeks the Messiah will be cut off and have nothing, and the people of the prince who is to come will destroy the city and the sanctuary And its end will come with a flood; even to the end there will be war; desolations are determined. And he will make a firm covenant with the many for one week, but in the middle of the week he will put a stop to sacrifice and grain offering; and on the wing of abominations will come one who makes desolate, even until a complete destruction, one that is decreed, is poured out on the one who makes desolate."_{[Dn 9:26-27]}

So, after the 483 years, the Messiah is crucified, the city and the sanctuary are destroyed, and there will continue to be war to the end. But, a prince (the Antichrist) will make a covenant with Israel for 7 years (the last week) and break it in the middle (see the book of Revelation for the full story).

So, what about this gap between the first 69 weeks and the last week where war and desolations are determined; what about this mystery timeframe. This mystery hidden in past ages has now been explained – the mystery is the church. The “fullness of the Gentiles” has to come in. Then, in the last week, the wrath of God will come upon the earth, Jesus will return, and the nation of Israel will be re-established.

This mystery is that through the gospel the Gentiles are heirs together with Israel, members together of one body, and sharers together in the promise in Christ Jesus._{[Eph 3:6 NIV]}

For I do not want you, brethren, to be uninformed of this mystery--so that you will not be wise in your own estimation--that a partial hardening has happened to Israel until the fullness of the Gentiles has come in;_{[Rom 11:25]}