Before the Second Coming perhaps.
“Therefore also said the wisdom of God, I will send them prophets and apostles, and some of them they shall slay and persecute: that the blood of all the prophets, which was shed from the foundation of the world, may be required of this generation; from the blood of Abel unto the blood of Zacharias, which perished between the altar and the temple: verily I say unto you, It shall be required of this generation.”
Luke 11:49-51
“As for these things which ye behold, the days will come, in the which there shall not be left one stone upon another, that shall not be thrown down. And they asked him, saying, Master, but when shall these things be?
Luke 21:6-7 KJV
……“Verily I say unto you, This generation shall not pass away, till all be fulfilled.”
Luke 21:32
“Verily I say unto you, All these things shall come upon this generation.”
Matthew 23:36 KJV
“Verily I say unto you, This generation shall not pass, till all these things be fulfilled.”
Matthew 24:34 KJV
“Verily I say unto you, that this generation shall not pass, till all these things be done.”
Mark 13:30 KJV
It could be that the truth is like he’s saying about Jerusalems destruction and desolation when Jesus said it would happen and those things he’s telling them would be fulfilled