"But when you see Jerusalem surrounded by armies, then know that its desolation is at hand.
Lk 21:20-24 refers to the siege by Titus, A.D. 70, when the city was taken, and verse 24 literally fulfilled. But that siege and its horrors but outline the final siege at the end of this age, in which the "great tribulation" culminates. At that time the city will be taken, but delivered by the glorious appearing of the Lord Rev 19:11-21. The references in Mt 24:15-28, Mk 13:14-26 are to the final tribulation siege; Lk 21:20-24 to the destruction of Jerusalem by Titus. In Luke the sign is the compassing of Jerusalem by armies Lk 21:20 in Mt 24:15 Mk 13:14 the sign is the abomination in the holy place. 2Th 2:4.