Yep, so if there was a time of vengeance for killing the prophets like Jesus said and there was the total destruction of the temple and Jerusalem in 70AD.....approx. 40 yrs from the cross. That generation just as Jesus said.
I'm not saying that this has anything to do with Rev., What I am saying is that when some teachers use this scripture to try to say this great tribulation is in the future they are misusing this scripture to back up what they think Rev. is saying about a future tribulation. And seeing this scripture directly points to Daniel 9 we cannot put Daniel 9 out in the future either. How does Daniel 9 tells us what time period he is talking about in those verses, because it is talking about when the Messiah came and what He did.
If one believes that Matthew 24 is in the future, they have no choice but to believe that God is going to bring judgment on the Jews Again for what they did to the prophets, apostles, etc. Because that is what the scripture says. That is why a great tribulation came on that generation.
If one says it is a double prophecy, as some do, they have to believe the same thing. It doesn't say anything about changing hearts to God. It says it is a "day of vengeance."