Luke 21:21-22

Then the Jews should get away from the city. Those in it should leave, those outside it should not enter it while it would be under siege, and those living in the surrounding area should move farther from it. God’s vengeance on the city would descend shortly in fulfillment of prophecy (Daniel 9:26).

Earlier Luke recorded Jesus’ teaching about the destruction that would come on Palestine just before His return (Luke 17:22-37). Matthew and Mark wrote that Jesus also gave that teaching in the Olivet Discourse (Matthew 24:15-22; Mark 13:14-20). However though that teaching is similar, it is different from what Jesus announced here. Here He predicted the destruction of Jerusalem that happened in A.D. 70.

"In fact, when the Romans were beginning to invest Jerusalem, the local Christians mostly fled to Pella, one of the cities of Decapolis and situated in trans-Jordan, south of the sea of Galilee (Eusebius says they went in response to ’an oracle given by revelation’, which may mean Jesus’ words or a later injunction of a similar kind from a Christian prophet; see Historia Ecclesiastica III. Luke 21:3)." [Note: Morris, pp. 298-99.]