Hilary of Poitiers

Or otherwise; It is a sign of His future coming that the Lord gives, when He says, When ye shall see the abomination. For the Prophet spoke this of the times of Antichrist; and he calls abomination that which coming against God claims to itself the honour of God. It is the abomination of desolation, because it will desolate the earth with wars and slaughter; and it is admitted by the Jews, and set up in the holy place, that where God had been invoked by the prayers of the saints, into that same place admitted by the unbelievers it might be adored with the worship of God. And because this error will be peculiar to the Jews, that having rejected the truth they should adopt a lie, He warns them to leave Judæa, and flee to the mountains, that no pollution or infection might be gathered by admixture with a people who should believe on Antichrist. That He says, Let him which is on the housetop not come down to take ang thing out of his house, is thus understood. The roof is the highest part of the house, the summit and perfection of the whole building. He then who stands on the top of his house, i. e. in the perfection of his heart, aloft in the regeneration of a new spirit, ought not to come down to the lower desire of things of the world. Neither let him which is in the field return back to take his coat; i. e. He that has attained to obedience to the command, let him not return back to his former cares, to take on him again the coat of his former sins in which he once was clothed.