PSac,
Was it literal? was if figurative? did he even say it ?
Good question? When we consider that Jesus "words" were spoken to a bunch of unlettered men who didn't even read nor write and the gospels were written decades of years latter.
We have the very real problem of accurate recall and misunderstanding of what was actually said. And we all know what happens when we pass on verbal data in a group and how it gets distorted the more links in chain the verbal message has to go through or the longer the time is from the initial message to the time it gets written down.
Of course many simply rely on the assumption that holy spirit guaranteed that the message would be unchanged a leave it at that. Add to this that these gospels were written down after 70 ce we have the very real problem of writing this down as a prophecy after the fact and pawning it off as a prediction that was fulfilled.
http://www.earlychristianwritings.com/matthew.html
Beare offers the following to date the Gospel of Matthew (op. cit., pp. 7-8):
It is generally agreed that it was written after the fall of Jerusalem to the armies of Titus (AD 70), and the widespread acquaintance with it which is exhibited in all the Christian literature of the second century makes it difficult to place its composition any later than the opening decade of that century. If the Sermon on the Mount can be regarded in any sense as 'the Christian answer to Jamnia. . . a kind of Christian mishnaic counterpart to the formulation taking place there' (Davies, Setting, p. 315), this would indicate a date a few years before or after the turn of the century.
Concerning the knowledge of the fall of Jerusalem that the author evinces, Schweizer writes concerning Matthew 22:7 (op. cit., p. 418):
The wrath of the host is mentioned by both evangelists, but it is impossible to conceive of the king coming with his army not only to slay those who had been invited but to burn down their city (not "cities"), and doing all this while the feast stands ready for the newly invited. The parable deals with ordinary citizens, who buy fields and use oxen, not with men who rule entire cities. After his punishment, furthermore, the verdict of the king in verse 8 is pointless. Verses 6-7 are thus clearly an interpolation in the narrative, which earlier passed directly from verse 5 to the wrath of the king (beginning of vs. 7), and then to verse 8. Here the events of A.D. 70 - the taking and burning of Jerusalem by Roman armies - have colored the language of the parable.