"For wherever the carcass is, there the eagles will be gathered together" (cf. Luke 17:37). Many believe that "eagles" would be better rendered as "vultures." As a dead body attracts vultures, so would Jerusalem, the spiritually-dead center of the Jewish nation, attract those who would devour it.
Our Lord continued speaking in Matthew 24:29,30 - "Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light; the stars will fall from heaven, and the powers of the heavens will be shaken. Then the sign of the Son of Man will appear in heaven, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory."
These verses use such strong and vivid language that most automatically assume that they could refer to nothing else but the end of the world and the second coming of Christ. If it were not for the contextual time limit in Matthew 24:34 (and the use of the word "immediately"), this would be the most-reasonable interpretation. However, because the events described herein occurred within that generation, the language here must not be describing the end of the world. When one examines other passages that use similar prophetic, apocalyptic language, one can rightly conclude that Jesus is here talking about the passing away of Judaism. Take the time to consider the following passages, all of which are describing the downfall of various nations, not the end of the world: Isaiah 13:10; 34:4,5; Ezekiel 32:7,8. Since such language was used in the Old Testament to describe the destruction of nations, it is not surprising that Jesus used similar language here. In so doing, He is emphasizing the fact that Jerusalem's destruction would be an outpouring of wrath from God. The signs in the heavens, the darkening sun, and the falling stars all refer to the final downfall of Judaism and the casting down of Jewish authorities and power.
"Then the sign of the Son of Man will appear in heaven" - Notice that the text does not say that Jesus would literally appear in heaven; it says that His "sign" would appear. "Then all the tribes of the earth will mourn" - When the Jews scattered throughout the world heard of the destruction of Jerusalem, there would be great mourning.
"They will see the Son of Man coming on the clouds of heaven with power and great glory" (cf. Isa. 19:1). Jesus was basically saying that they would see Him, through His avenging acts of judgment, coming upon Jerusalem with authority and might (via the Romans). This was most likely the "sign" of His coming.
Interestingly, Josephus and other first-century historians did record some unusual phenomena in A.D. 70 (e.g., fiery meteors, a comet pointing down to the city, and "a flaming sword" hanging in the sky; cf. Joel 2:30,31). Many also documented the continual pillars of smoke rising into the air from the burning city.
We will continue studying this passage in our next lesson.