Daniel 9 opens with Daniel at the "tender, young age" of 87. He knew from Jeremiah's writings that the desolation of Jerusalem was prophesied to last for 70 years, and they had been fulfilled. Since God is faithful, Daniel knew that it was time for God to act. So he prayed to God, confessing on behalf of the nation and beseeching God to turn away His anger toward Jerusalem, even though the nation deserved everything that had happened and much more. He asks God, because of His great mercy, to hear, to forgive, to listen, and to act on behalf of His people (Daniel 9:4-19).

In response, the angel Gabriel comes to Daniel and gives him a prophecy (Daniel 9:20-23). God does more than just give the command for Jerusalem to be rebuilt: He actually outlines what He would do to solve Israel's problems once and for all. The problems, of course, were sin and rebellion against God—unbelief—and so His response to Daniel is a promise that these things would be overcome. God, through Gabriel, tells Daniel that "seventy sevens" (of years; 490 years) had been decreed, and when that span of time ran out, some truly remarkable things will have happened, to say the least.

Daniel 9:24 shows the scope of what God will accomplish by the time the seventy sevens of years are complete:

Seventy weeks are determined for your people and for your holy city, to finish the transgression, to make an end of sins, to make reconciliation for iniquity, to bring in everlasting righteousness, to seal up vision and prophecy, and to anoint the Most Holy.

God presents six elements that He will accomplish within the 490 years. It is His outline for what will happen in order for Daniel's people to be spiritually restored. In verses 25-27 He tells, in general terms, how that will happen:

Know therefore and understand, that from the going forth of the command to restore and build Jerusalem until Messiah the Prince, there shall be seven weeks and sixty-two weeks; the street shall be built again, and the wall, even in troublesome times. And after the sixty-two weeks Messiah shall be cut off, but not for Himself; and the people of the prince who is to come shall destroy the city and the sanctuary. The end of it shall be with a flood, and till the end of the war desolations are determined. Then [H]e shall confirm a covenant with many for one week; but in the middle of the week [H]e shall bring an end to sacrifice and offering. And on the wing of abominations shall be one who makes desolate, even until the consummation, which is determined, is poured out on the desolate.

Verses 26-27 show that all six of verse 24's elements will be accomplished through the arrival of the Messiah, His being cut off, and His confirming the New Covenant with many. Though much could be written about each of these six, Adam Clarke's Commentary summarizes them:

I. To finish (to restrain) the transgression, which was effected by the preaching of the Gospel, and pouring out of the Holy Spirit among men.

II. To make an end of sins; rather, "to make an end of sin-offerings"; which our Lord did when he offered his spotless soul and body on the cross once for all.

III. To make reconciliation ("to make atonement or expiation") for iniquity; which he did by the once offering up of himself.

IV. To bring in everlasting righteousness, that is, "the righteousness, or righteous ONE, of ages"; that person who had been the object of the faith of mankind, and the subject of the predictions of the prophets through all the ages of the world.

V. To seal up ("to finish or complete") the vision and prophecy; that is, to put an end to the necessity of any further revelations, by completing the canon of Scripture, and fulfilling the prophecies which related to His person, sacrifice, and the glory that should follow.

VI. And to anoint the Most Holy, "the Holy of holies." . . . Here it means the consecration or appointment of our blessed Lord, the Holy One of Israel, to be the Prophet, Priest, and King of mankind.

Notice in particular the fifth element, "to seal up vision and prophecy." What it means is to make an end of vision and prophecy by fulfilling it. In other words, when the seventy sevens are finished, the visions and prophecies will all be wrapped up. What is not certain is the scope of the phrase "vision and prophecy." It may refer to just those found in the book of Daniel, or it could refer to all the visions and prophecies given to that point. What is significant is that, at the end of the 490 years, a majority, if not the entirety, of the Old Testament prophecies will have had their fulfillment.