Luke 21:20,21 - Joseph Benson’s Commentary on the Old and New Testaments

And when ye shall see Jerusalem encompassed with armies, &c. The admonition here given to them who were in the midst of Jerusalem to depart out of it, and to them who were in the countries not to enter thereinto, shows that the encompassing of Jerusalem with armies, spoken of in the prophecy, was such as would permit the inhabitants to flee out of it, and those who were in the countries to enter into it. Behold here the wonderful prescience of Jesus! Cestius Gallus, in the beginning of the war, invested Jerusalem, and took Betheza, or the lower town. Josephus, (Bell., Luke 2:24,) says, “If he had continued the siege but a little longer, he would have taken the city. But, I think, God being angry with the wicked, would not suffer the war to end at that time. For Cestius removed his army, and having received no loss, very unadvisedly departed from the city.” And, chap. 25. of the same book, he further informs us, that “immediately after Cestius's departure, many of the principal Jews daily fled from the city as from a sinking ship.” Among these, we may believe there were numbers of the Christians, who, remembering their Master's admonition, and foreseeing what was to happen, embraced the opportunity thus afforded them of fleeing out of Judea, and so escaped the general ruin, as their Master had promised them, Matthew 24:13; Luke 21:18. To this agrees what Eusebius tells us, (Hist., Luke 3:5,) “That the people of the church in Jerusalem, being ordered by an oracle, given to the faithful in that place, left the city before the war, and dwelt in a city of Perea, the name of which was Pella.” This oracle, of which he speaks, seems to have been our Lord's prophecy and admonition, to which every circumstance of the history perfectly agrees.