{30} "And then the sign of the Son of Man will appear in the sky, and then all the tribes of the earth will mourn, and they will see the SON OF MAN COMING ON THE CLOUDS OF THE SKY with power and great glory. Matthew 24:30 (NASB)
{7} BEHOLD, HE IS COMING WITH THE CLOUDS, and every eye will see Him, even those who pierced Him; and all the tribes of the earth will mourn over Him. So it is to be. Amen. Revelation 1:7 (NASB)
Same event, right?
Now here's EXACTLY what it means and where it came from:
"I will pour out on the house of David and on the inhabitants of Jerusalem, the Spirit of grace and of supplication, so that they will look on Me whom they have pierced; and they will mourn for Him, as one mourns for an only son, and they will weep bitterly over Him like the bitter weeping over a firstborn.
{11}"In that day there will be great mourning in Jerusalem, like the mourning of Hadadrimmon in the plain of Megiddo. {12}"The land will mourn, every family by itself; the family of the house of David by itself and their wives by themselves; the family of the house of Nathan by itself and their wives by themselves; {13} the family of the house of Levi by itself and their wives by themselves; the family of the Shimeites by itself and their wives by themselves; {14} all the families that remain, every family by itself and their wives by themselves. Zechariah 12:11-14 (NASB)
Every tribe and family of the land of Israel saw whom they pierced when Jesus Christ - the Lamb that was slain - returned in judgment upon Jerusalem for rejecting Him.
They were warned in Leviticus 26 what would happened if they acted with hostility toward God and broke His covenant.
They were warned by Christ what would happen to them in Matthew 21-23 and Luke 19-21 if they rejected Him.
They called His blood down on themselves and their children, and God Himself used the Romans to execute judgment on them for killing His son (see the parable of the landowner in Matthew 21).
In short, people need to start rethinking what these terms mean from the perspective of a first century Jew, NOT from that of a 21st century American "Fundy" Evangelical!
I don't know how much plainer it can be.
Start crackin' open the Old Testament, people. That's where the keys are to unlocking Revelation.