What does Mark 13:16 mean?

Jesus is warning the Jews how urgent the danger will be at the midpoint of the tribulation. The Antichrist will fully reveal that he is the enemy of Israel, not its peace-broker (Daniel 9:27; Revelation 12:6, 13–17). He will build a statue for the world to worship (Daniel 9:27; 12:11; 2 Thessalonians 2:4; Revelation 13:15) and defile Jerusalem in a manner similar to Antiochus Epiphanes who sacrificed a pig to Zeus in God's temple. When this happens, Jews will barely have enough time to flee the city. Some see at least a partial fulfillment of this in the tragic events of 70 AD, when Jerusalem was sacked and the temple destroyed.

In Bible times, the cloak, the robe that is worn over the clothes, is a necessary accessory. The Mosaic law specifically states that if a man borrows money and leaves his cloak as collateral, the lender is required to return the cloak at the end of the day because it may be the man's only protection from the cold (Exodus 22:26–27). During the day, working in the fields, a cloak might not be necessary so it was left at the corner of the field. At night, fleeing to the hills, it certainly would be. And yet the coming danger is such that even the threat of cold nights is no comparison; there won't even be time to go to the corner of the field before the people need to go.

If the times of the tribulation are more like the modern day than Jesus' era, we can extrapolate what it might mean to those who live through it: Do not go back for your phone chargers. Leave your pets. Do not go home to pack food or get extra insulin or heart medication. There is no time to grab passports or birth certificates. Just run.