Hi joi,
I'm new here, but I wanted to offer a slightly modified view from what retro offered. Retro says that the 'he' of vs. 27 cannot be the prince that shall come. But I ask this question: "Where in Daniel 9 did it mentioned anyone other than the Messiah before that?" In Retro's case, Daniel just forces in a character that was not previously described to him as though he understood quite well who it was. In the case of my argument, the Messiah is the prince who shall come. And I will defend that argument.
To start, I want to offer up Jesus' parable of the wedding feast in Matthew 22:1-14.
"And again Jesus spoke to them in parables, saying, "The kingdom of heaven may be compared to a king who gave a wedding feast for his son, and sent his servants to call those who were invited to the wedding feast, but they would not come. Again he sent other servants, saying, "Tell those who are invited, See, I have prepared my dinner, my oxen and my fat calves have been slaughtered, and everything is ready. Come to the wedding feast." But they paid no attention and went off, one to his farm, another to his business, while the rest seized his servants, treated them shamefully, and killed them. The king was angry, and he sent his troops and destroyed those murderers and burned their city. Then he said to his servants, "The wedding feast is ready, but those invited were not worthy. Go therefore to the main roads and invite to the wedding feast as many as you find." And those servants went out into the roads and gathered all whom they found, both bad and good. So the wedding hall was filled with guests. "But when the king came in to look at the guests, he saw there a man who had no wedding garment. And he said to him, "Friend, how did you get in here without a wedding garment?" And he was speechless. Then the king said to the attendants, "Bind him hand and foot and cast him into the outer darkness. In that place there will be weeping and gnashing of teeth." For many are called, but few are chosen." (Matthew 22:1-14 ESV)"
Notice in the passage that the king, whom is obviously God, sends HIS troops to destroy the city, which is obviously Jerusalem. Then every other nation and city is invited to the wedding feast, which is the kingdom of God; or the Abrahamic Covenant. I want to bring up another parable:
""Hear another parable. There was a master of a house who planted a vineyard and put a fence around it and dug a winepress in it and built a tower and leased it to tenants, and went into another country. When the season for fruit drew near, he sent his servants to the tenants to get his fruit. And the tenants took his servants and beat one, killed another, and stoned another. Again he sent other servants, more than the first. And they did the same to them. But when the tenants saw the son, they said to themselves, "This is the heir. Come, let us kill him and have his inheritance." And they took him and threw him out of the vineyard and killed him. When therefore the owner of the vineyard comes, what will he do to those tenants?" They said to him, "He will put those wretches to a miserable death and let out the vineyard to other tenants who will give him the fruits in their seasons." Jesus said to them, "Have you never read in the Scriptures: "The stone that the builders rejected has become the cornerstone; this was the Lord's doing, and it is marvelous in our eyes"? Therefore I tell you, the kingdom of God will be taken away from you and given to a people producing its fruits. And the one who falls on this stone will be broken to pieces; and when it falls on anyone, it will crush him." When the chief priests and the Pharisees heard his parables, they perceived that he was speaking about them." (Matthew 21:33-36, 38-45 ESV)
In a nutshell, Jesus was telling the Pharisees that the kingdom of God was going to be taken away from the Jews and be given to the Gentiles. The Gentiles would be blessed because of His servants. So, the Romans were the people of the Messiah. I know it sounds outrageous, but its true.
In the Middle East, when a king such as Nebuchadnezzar would set his image or ensign in a place he conquered, it meant that the dominion belonged to him. In the same way, when the first disciples were persecuted, they established churches in every place they fled to. This was Jesus setting up His ensign. This is even confirmed in Matthew 28:18, where Jesus says, "All authority in heaven and on earth has been given to me..." So every nation that the church was established became the nation of God and His Son. But it was not so with Jerusalem. Jesus said to His disciples: "You are the salt of the earth. If the earth loses its saltiness, what good is it but to be trampled underfoot?" So, like when Sodom was only destroyed after Lot fled, Jerusalem was destroyed only after the disciples fled.
And one more thing about the seventieth week: The covenant that Jesus confirmed with many was the Abrahamic Covenant. And the many were the Gentiles. That is consistent in the parables and all throughout the Gospel. The Abrahamic Covenant stated that God would make Abraham's seed countless. In Revelation 7:9-10, we see that was fulfilled among the Gentiles. The Abrahamic Covenant stated that God would bless all families of the earth through him, and we find that fulfilled to this day among the many nations that are blessed because of the saints among the Gentiles.
"For there is no distinction between Jew and Greek; for the same Lord is Lord of all, bestowing his riches on all who call on him." (Romans 10:12 ESV)
I know this post has been long. I just wanted to adequately defend my argument. Daniel 9:26 shows that the Messiah would be rejected and that God would send the Romans to destroy the city and sanctuary, which was fulfilled. Daniel 9:27 indicates that the Messiah would take the Abrahamic Covenant away from many of the Jews and give it to the Gentiles. That happened when the disciples were chased out of Jerusalem. From that point on, Jerusalem had 3.5 years left. During that time, Jerusalem would become a beacon for every wicked criminal, which Flavius Josephus records was fulfilled with John of Gischala. The war on Jerusalem lasted from 66 CE to 70 CE, approximately 3.5 years.