Matthew 24:17 Meaning

15When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, (whoso readeth, let him understand:)

16Then let them which be in Judaea flee into the mountains:

17Let him which is on the housetop not come down to take any thing out of his house:

18Neither let him which is in the field return back to take his clothes.

19And woe unto them that are with child, and to them that give suck in those days!