This is almost the same, word for word, in Mark, chapter 13:16, but not in Luke. If you were in the field working (καὶ ὁ ἐν τῷ ἀγρῷ), you were not to turn back or return to your house (μὴ ἐπιστρεψάτω ὀπίσω) to get or take a coat or outer garment (ἆραι τὸ ἱμάτιον αὐτοῦ). You had no need for clothes because the end was near.
The northern Israelites were in a unique position. They would sow with the wind, but it suddenly would become a whirlwind. The planted grain would never mature in the field, since there would be no heads of grain. Therefore, there would be no harvesting of the grain for meals. Even if it yielded any grain, foreigners, and not them, would devour it, because of the invasion of the Assyrians.