You are misreading these texts:
Albert Barnes (1832)
"The coming of the Son of man. It has been doubted whether this refers to the destruction of Jerusalem, or to the coming at the day of judgment. For the solution of this doubt, let it be remarked,
(1.) that those two events are the principal scenes in which our Lord said he would come, either in person or in judgment.
(2.) That the destruction of Jerusalem is described as his coming, his act, for their great crimes.
(3.) That these events--the judgment of Jerusalem and the final judgment --in many respects greatly resemble each other.
(4.) That they will bear, therefore, to be described in the same language. And,
(5.) therefore, that the same words often include both events, as properly described by them. The words, therefore, had doubtless a primary reference to the destruction of Jerusalem, but such an amplitude of meaning as also to express his coming to judgment.
Verse 28. Wheresoever, etc. The words in this verse are proverbial. Vultures and eagles easily ascertain where dead bodies are, and come to devour them. So with the Roman army. Jerusalem is like a dead and putrid corpse. Its life is gone, and it is ready to be devoured. The Roman armies will find it out, as the vultures do a dead carcass, and will come around it, to devour it.
This verse is connected with the preceding by the word "for," implying that this is a reason for what is said there, that the Son of man would certainly come to destroy the city, and that he would come suddenly. The meaning is, he would come by means of the Roman armies, as certainly, as suddenly, and as unexpectedly, as whole flocks of vultures and eagles, though unseen before, suddenly find their prey, see it at a great distance, and gather in multitudes around it. Travellers in the deserts of Arabia tell us that they sometimes witness a speck in the distant sky, which for a long time is scarcely visible. At length, it grows larger; it comes nearer; and they at last find that it is a vulture, that has from an immense distance seen a carcass lying on the sand. So keen is their vision, and so aptly does this represent the Roman armies, though at an immense distance, yet spying, as it were, Jerusalem, a putrid carcass, and hastening in multitudes to destroy it.
Verse 30. The sign of the Son of man. The evidence that Christ is coming to destroy the city of Jerusalem. It is not to be denied, however, that this description is applicable also to his coming at the day of judgment. The disciples had asked him, Matthew 24:3 what should be the sign of his coming, and of the end of the world. In his answer, he has reference to both events, and his language may be regarded as descriptive of both. At the destruction of Jerusalem, the sign or evidence of his coming was found in the fulfillment of these predictions.
All the tribes of the earth mourn. This is, either all the tribes or people of the land of Judea shall mourn at the great calamities coming upon them, or all the nations of the world shall wail when He comes to judgment. All the wicked shall mourn at the prospect of their doom, Revelation 1:7.
And they shall see the Son of man. The Lord Jesus coming to judgment. Probably this refers more directly to his coming at the last day, though it may also mean that the evidence of his coming to destroy Jerusalem shall then be seen.
With power. Power, manifest in the destruction of Jerusalem, by the wonders that preceded it, and by the overturning of the temple and city. "
Kenneth L. Gentry (1999)
"Jesus warns His followers that He will not appear bodily in the first-century judgment (vv. 23-26). Nevertheless, He will "come" in judgment like a destructive lightening bolt against Jerusalem (v.27). This coming, however, is a providential judgment coming, a Christ-directed judgment, rather than a miraculous, visible, bodily coming.
Nor is the coming as lightening in Matthew 24:27 a publicly visible, physical coming. Rather, it is a judgment coming against those who call down Jesus' blood upon them and their children (v.25). The Lord here speaks about His judgment coming against Jerusalem (see 23:37-24:2) as analogous to "the lightening [that] comes from the east, and flashes even to the west." As I begin to interpret the passage, remember that the local context demands this coming occur in "this generation" (24:34), having reference to the destruction of the temple.
The direction of this judgment coming of Christ in Matthew 24:27 apparently reflects the Roman armies marching toward Jerusalem from an easterly direction. Josephus' record of the march of the Roman armies through Israel shows they wreak havoc on Jerusalem by approaching it from the east." (The Great Tribulation: Past or Future?, MI: Kregel, 1999, p. 53-54; cf. Josephus' Wars 4:8:1; 4:9:1)
