Sticking with Matthew’s presentation for the purposes of this analysis, the reader is now in a state of superior comprehension of the words of Jesus when hearing such things as “Whenever they persecute you in one place, flee to another. I tell you the truth, you will not finish going through all the towns of Israel before the Son of Man comes” (10:23); “The Son of Man will send His angels, and they will gather from His kingdom everything that causes sin as well as all lawbreakers” (13:41); “For the Son of Man will come with His angels in the glory of His Father, and then He will reward each person according to what He has done” (16:27)---a clear Daniel seven reference; and “I tell you the truth, there are some standing here who will not experience death before they see the Son of Man coming in His kingdom” (16:28). It is now understood that the last of these mentions of the Son of Man can be equated with the fall of the Temple, as would be made clear later in Matthew. For the followers of Jesus then, seeing the Son of Man coming in His kingdom was the same thing as seeing the Temple fall.
Something mentioned within the previous analysis of second Peter, which was the fact that talk of “heaven and earth” was a common way of referencing the Temple, leads back to that which precedes Jesus’ statement that “as for that day and hour no one knows it---not even the angels in heaven---except the Father alone” (Matthew 24:36). Just before Jesus says this, and immediately after He speaks about the generation that will see the Temple fall, Jesus says “Heaven and earth will pass away, but My words will never pass away” (24:35).
This, as has been alluded to several times, is also identically reported by the three evangelists---a fact that, like the other identically reported statement that preceded it, should not escape attention. Now, does one take this statement, allow imagination to wander about again, and hear Jesus going off on a tangent about the end of the world when He speaks these words, or is to be heard within context, speaking in a very understandable way? Obviously, the latter option is the more prudent and proper choice.
Jesus has not changed the subject. Jesus has not gone off on a tangent. He is speaking about the fall of the Temple. He is continuing to answer the question posed to Him at the beginning of the chapter following His declaration that not one stone of the Temple would be left upon another, as to when this would happen. He has given the bulk of His answer, telling His disciples and other hearers the types of things that they would see and which should prepare them for the Temple’s fall, and re-asserts the finality of His prediction when He says that “Heaven and earth,” the Temple, “will pass away, but My words,” this prediction, “will not pass away.”
In other words, Jesus says, “Oh yes, the Temple is going to fall. You can count on it happening.” Beyond that, one can hear Him making an existential claim, in that even though the Temple will pass away, His words---words that spring from the true Temple, will never pass away. Also, because it is coincident with the fall of the Temple that Jesus (the Son of Man) will be going before the Father (the Ancient of Days) to receive His kingdom, those who are listening to Him, and those who come to believe in Him through the preaching of His disciples, can have confidence that His words are words that will endure. His words about the Temple will indeed prove to be true---they will never pass away. History will prove Him correct and He will reign as the Son of Man.