Luk 21:20-21  And when ye shall see Jerusalem compassed with armies, then know that the desolation thereof is nigh. Then let them which are in Judaea flee to the mountains; and let them which are in the midst of it depart out; and let not them that are in the countries enter thereinto. For these be the days of vengeance, that all things which are written may be fulfilled. 

Before the destruction of Jerusalem in 70 A.D. believers, based on the instructions of Yahshua, Jesus, left the city and fled to Pella, across the Jordan River.

To Learn more read Time is the Ally of Deceit – Chapter One – Flee to the Mountains