Just to elaborate a little...and I'm not to sure of the sources of some of the marterial below...but some I derived from Marcellus Kik's book "Matthew 24" which was the eye-opener for me on this subject.
30. AND THEN SHALL APPEAR THE SIGN OF THE SON OF
MAN IN HEAVEN: AND THEN SHALL ALL THE TRIBES
OF THE EARTH MOURN, AND THEY SHALL SEE THE SON
OF MAN COMING IN THE CLOUDS OF HEAVEN WITH
POWER AND GREAT GLORY. (See Jer.21:5 Is.19:1)
Note that it is "the sign of the Son of Man in heaven", not the Son
of man visiting the earth. At the destruction of Jerusalem, the sign
or precursor to His coming to destroy was found in the fulfillment
of these predicted calamities and finally the surrounding of
Jerusalem by the Roman armies. Of course as these calamities and
ultimate destruction, befell them, the tribes would mourn. The
Jews were eventually left without temple, city, sacrifice or
priesthood as was prophesied by Daniel.
Mat 24:30 -
Then shall appear the sign of the Son of man - The plain meaning of this is, that the destruction of Jerusalem will be such a remarkable instance of Divine vengeance, such a signal manifestation of Christ’s power and glory, that all the Jewish tribes shall mourn, and many will, in consequence of this manifestation of God, be led to acknowledge Christ and his religion. By της γης , of the land, in the text, is evidently meant here, as in several other places, the land of Judea and its tribes, either its then inhabitants, or the Jewish people wherever found.
AND THEY SHALL SEE THE SON OF MAN COMING IN
THE CLOUDS OF HEAVEN WITH POWER AND GREAT
GLORY.
Does the phrase "coming ( ε?´ρχομαι erchomai) in the clouds"
necessarily refer to a personal coming to earth? We should not
read that thought into the text. Is. 19:1 states "See the Lord rides
on a swift cloud and is coming to Egypt: and the idols of Egypt
shall be moved at His presence, and the heart of Egypt shall melt in
the midst of it" Although this verse speaks of the Lord riding on a
cloud and of His presence, we know that the Egyptians did not see
the Lord in a personal and visible way. The expression is rather
used to indicate a coming in judgment against Egypt. Jesus
coming in the clouds against Israel thus refers to a similar kind of
judgment.
The clouds of heaven obscure or shut heaven from man's view.
They were to see the Lord Jesus coming to judgment with power.
This power was manifest in the destruction. The word glory refers
to the visible display of his honor, power and majesty.
That Jesus destroyed the city in 70 AD is accurate. As Daniel 9:27
reveals; because of the over spreading of abominations, he, the
Lord and Messiah himself would make it desolate (Titus
merely being his instrument.) Confirmation is found in Jesus' exclusion parables.
Mt.21: 40 When the lord therefore of the vineyard cometh
( ε?´ρχομαι erchomai) , what will he do unto those husbandmen?
41 They say unto him, He will miserably destroy those wicked
men, and will let out his vineyard unto other husbandmen, which
shall render him the fruits in their seasons. See also Lu.20:15,16
The timing on this is relevant this coming in vengeance, would climax the
tribulation and occur in the lifespan of Christ's own generation.
Mat 16:28 Verily I say unto you, There be some standing here, which
shall not taste of death, till they see the Son of man coming
( ε?´ρχομαι erchomai) in his kingdom. (Mt.10:23 Lu.9:27)
Finally, in the often-overlooked trial scene in 26:64, Jesus says to the high priest that “ from now on you will see the son of man seated at the right hand of Power and coming on the clouds of heaven.”
The key phrase in that last passage is “from now on”, which is about as close as Matthew comes to the outright investment of glory which John gives to the cross when he attests Jesus as saying things like “Now the son of man is glorified”, “Now is the judgment of this world; now will the ruler of this world be cast out”, and “When I am lifted up from the earth, I will draw all people to myself” (John 12:31, 32; 13:31). The conviction which both Matthew and John unambiguously express is that the exaltation of the son of man would be seen not merely at the end of history but also in the matrix of events unfolding from his messianic work in the middle of history.