The mainstream consensus is that it was written in the 90’s under Domitian. It is decidedly unscholarly to posit the existence of supernatural prophecy.
What “event”?
The event to which the statement refers is the purported revelation to its author. I am guessing that, in this case, the recording of events refers only to the Gospels, the Acts of the Apostles, and Revelation. I’m pretty sure that the authentic Pauline Epistles were written as soon as Paul felt the need to write them. (It would be pretty silly for Paul to have sent Onesimus home to resume his servitude in the house of Philemon, then written Philemon a letter expaining his actions two or three years later. )
This, of course, presupposes that the revelation so recorded was an actual vision and that the work was not a carefully planned and executed piece of writing that drew on a tradition of similar writings that had been produced for nearly 300 years, (building on a similar, if less fully developed tradition that was nearly 600 years old).
Prophecy does not have to be supernatural. Jewish rebellion was in the air at the time. On the other hand it is decidedly incredulous to believe that a man would write a prophecy predicting the destruction of Jerusalem 30 some odd years after the city had already been completely destroyed. (Unless of course John could see a millinium or two ahead )
Revelation does not contain a prediction of the destruction of Jerusalem. You used the word “incredulous” incorrectly, by the way.
I’d think that would make it easier to get it right. I mean, I’m sure I could come up with some bang-on prophecies about the election of Jimmy Carter, Camp David, stagflation, and the Soviet invasion of Afghanistan.
Mark used the device of placing a prediction of the destruction of the Temple on the lips of Jesus.
So did Luke, in 21:20-24
Revelations II
Yes, it indicates that the city has already been “given over to the gentiles.” Present tense. The book assumes that the reader already knows about the destruction of Jerusalem and speaks about the eventual restoration of the Temple. There are a number of internal markers which indicate that the book was written at the end of the 1st Century and there is no serious scholarship which dates it before the destruction of Jerusalem (though an argument can be made that the author wanted to give that illusion).
Also, Revelation 17.
The event is the revelation itself. The ‘vision’ happened, in the ‘revelation’ Jesus told St. John to write these things down. I think it’s pretty safe to conclude that St. John did write it down as soon as he could find a 1st century version of a pen and paper (or laptop).
I know this has been answered more or less, but here is the biblical explanation.
According to Genesis, Abraham’s wife, Sarah could not have children. Sarah had an Egyptian maid named Hagar. Sarah told Abraham to take Hagar as a wife to hopefully produce an heir, and Hagar did bear a son: Ishmael. (Gen. 16)
Late in Sarah’s life, God blessed her with a son: Isaac. It seems Hagar or Ishmael was jealous of Isaac, so Sarah told Abraham to cast out Hagar and her son. Abraham did not want to drive out Hagar and Ishmael, but God reassured him and told him to listen to Sarah.
In the wilderness, distressed and afraid, the Lord spoke to Hagar and told her not to fear because God would make Ishmael the father of a nation. God also provided a well of water to sustain them. (Gen. 21)
The well the Lord provided in the dessert is known as the well of Zamzam, a holy place in Islamic culture. Muslims believe they are decedents of Abraham through Ishmael. Jews believe they are decedents of Abraham through Isaac.
I agree. It seems Esau and Jacob reconciled. “Then Esau ran to meet him [Jacob] and embraced him, and fell on his neck and kissed him, and they wept.” (Gen. 33:4)
Jacob renamed Israel by God had twelve sons known as the twelve tribes of Israel. (Gen 35:23)
Ishmael also had twelve sons known as the twelve princess. (Gen. 25:12)
Um. . . decendents, not decedents. Although many who were decended are now dead.
Irrelevant. Rome occupied Jeruselem decades before the destruction.
Explain how John was expected to measure a structure that had been completely destroyed.
Well in that case I’d better shut up.
It was a visionary or “Heavenly” version of the Temple. It was the Temple to come, not the one which had been destroyed.
Well, I do make typing errors. Unfortunately, it is too late to edit, so thank you for the correction. I certainly don’t want the typo to confuse the reader. 
Either way, heavenly or not, you are still suggesting that the author reports he was asked to measure a non existing temple. And for what purpose? Is the author suggesting that the heavenly temple and new Jerusalem to come will be trampled again ? Just doesn’t make sense to me.
I’ll apply Occam’s Razor in this case.
I did mix up the 2, it was Jacob’s line was blessed with many children AND anointed, Ishmael’s line was blessed with many children.