But as for that day and hour no one knows it---not even the angels in heaven---except the Father alone. - Matthew 24:36 (NET)
If we hold to the idea that the early church, having rightly comprehended what Jesus meant by His fall-of-the-Temple-focused discourse (as recorded in Matthew 24, Mark 13, and Luke 21), tightly connected the fall of the Temple with the coming of the Son of Man to the Ancient of Days in order to receive His kingdom, then the heavy inclusion of all of the Son of Man language throughout the Gospels makes even greater sense. While we will not take the time to review all of the mentions of the Son of Man, it is worth taking a bit of time to review and to draw out some conclusions and inferences that would have been obvious to Jesus’ original audience.
In a superficial review, we notice that John has the fewest uses of “Son of Man.” Mark clocks in with the next fewest, while both Matthew and Luke are replete with its usage (Luke nearly doubling Mark’s count, while Matthew more than doubles Mark’s usage). While John obviously pursues its agenda on a different path than do the synoptics, Mark’s relative restraint in using the term is understandable if it is, in fact, cautiously and expectantly composed before the fall of the Temple. Of course, we do not simply assert that a lack of details in indicative of a pre-fall composition, as Mark could certainly have been just as precise and non-verbose, as opposed to his evangelistic counterparts, while writing after the Temple’s fall.
Once we hear correctly and contextually hear Jesus’ Son of Man language within His crystal clear, prophetical, and predictive speech about the coming fall of the Temple, doing so in the light of Daniel’s seventh chapter, we do ourselves a tremendous disservice if we do not reflect on a few of its appearances prior to the Temple speech in which Jesus connects the Temple’s fall with the Son of Man’s arrival and kingdom acquisition. Sticking with Matthew’s presentation for our purposes here, we find ourselves in a state of superior comprehension of the words of Jesus when we hear 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). We can comfortably equate the last of these mentions of the Son of Man with the fall of the Temple, as would be made clear later in Matthew. For the followers of Jesus, seeing the Son of Man coming in His kingdom was the same thing as seeing the Temple fall.
We must also make mention of the fact that talk of “heaven and earth,” in that day, was a common way of referencing the Temple. This leads us back to consider 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, though the synoptic authors disagree in so many of their details in their presentation of Jesus’ Temple-and-Son-of-Man focused apocalyptic discourse, is identically reported by the three evangelists---a fact that, like the other identically reported statement that preceded it (concerning the generation that would see the fall of the Temple), should not escape our attention. Now, do we let our imaginations wander about, causing us to hear Jesus going off on a tangent about the end of the world when He speaks these words, or do we hear Him within context, speaking in a very understandable way? Obviously, we should choose the latter option.
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,” perhaps 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, we 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.