Tobit 14:5
But God will again have mercy on them and bring them back to the land of Israel. They will build the house again, but it will not be like the first until the era when the appointed times will be completed.* Afterward all of them will return from their captivity, and they will rebuild Jerusalem with due honor. In it the house of God will also be rebuilt, just as the prophets of Israel said of it.Tobit was written in the 2nd century BCE, but, like Daniel, was cast in a setting centuries before. The author describes the destruction by Babylonians and return to Jerusalem as if they were prophecy. With the benefit of hindsight he was aware that the Temple was not fully rebuilt for decades after the return. He uses an expression "until appointed times are completed (fulfilled)" to suggest the delay was by God's providence.
The author of Luke saw a parallel with his time of apparent delay and apparently drew inspiration from this text and the repeated notion of appointed times from Daniel. So now we have a period of delay from the destruction of Jerusalem till the return of Jesus to usher in a golden age being inserted into the text of Mark.
Luke 21:24 They will fall by the sword and will be taken as prisoners to all the nations. Jerusalem will be trampled on by the Gentiles until the times of the Gentiles are fulfilled.