Ambrose of Milan — as excerpted in the Catena Aurea on Luke 21:20-24

“Now mystically, the abomination of desolation is the coming of Antichrist, for with ill-omened sacrilege he pollutes the innermost recesses of the heart, sitting as it is literally in the temple, that he may claim to himself the throne of divine power. But according to the spiritual meaning, he is well brought in, because he desires to impress firmly on the affections the footstep of his unbelief, disputing from the Scriptures that he is Christ. Then shall come desolation, for very many falling away shall depart from the true religion. Then shall be the day of the Lord, since as His first coming was to redeem sin, so also His second shall be to subdue iniquity, lest more should be carried away by the error of unbelief. There is also another Antichrist, that is, the Devil, who is trying to besiege Jerusalem, i. e. the peaceful soul, with the hosts of his law. When then the Devil is in the midst of the temple, there is the desolation of abomination. But when upon any one in trouble the spiritual presence of Christ has shone, the unjust one is cast out, and righteousness begins her reign. There is also a third Antichrist, as Arius and Sabellius and all who with evil purpose lead us astray. But these are they who are with child, to whom woe is denounced, who enlarge the size of their flesh, and the step of whose inmost soul waxes slow, as those who are worn out in virtue, pregnant with vice. But neither do those with child escape condemnation, who though firm in the resolution of good acts, have not yet yielded any fruits of the work undertaken. These are those which conceive from fear of God, but do not all bring forth. For there are some which thrust forth the word abortive before their delivery. There are others too which have Christ in the womb, but have not yet formed Him. Therefore she who brings forth righteousness, brings forth Christ. Let us also hasten to nourish our children, lest the day of judgment or death find us as it were the parents of an imperfect offspring. And this you will do if you keep all the words of righteousness in your heart, and wait not the time of old age, but in your earliest years, without corruption of your body, quickly conceive wisdom, quickly nourish it. But at the end shall all Judæa be made subject to the nations which shall believe, by the mouth of the spiritual sword, which is the two-edged word. (Rev. 1:16; 19:15.)”