In other words, Jesus thinks he is the Messiah ("Christ"/"anointed one") and conflates this status with Daniel's divine "son of man" in 8:31-32, which is the part that Peter has trouble understanding:Jesus and his disciples went on to the villages around Caesarea Philippi. On the way he asked them, “Who do people say I am?” They replied, “Some say John the Baptist; others say Elijah; and still others, one of the prophets.” “But what about you?” he asked. “Who do you say I am?” Peter answered, “You are the Messiah.” Jesus warned them not to tell anyone about him.
And I think the "must suffer"/"must be killed" part regarding this "Messiah"/"son of man" is due to Jesus' interpretation of Dan. 9:26, which mentions "an anointed one" who will be "cut off and have nothing":He then began to teach them that the Son of Man must suffer many things and be rejected by the elders, the chief priests and the teachers of the law, and that he must be killed and after three days rise again. He spoke plainly about this, and Peter took him aside and began to rebuke him.
So I think Jesus is conflating the divine "son of man" in Dan. 7:14 with the cut off "anointed one" in Dan. 9:26 (which in my view are separate things). I think this is also where Jesus gets his prediction that “Not one stone here will be left on another; every one will be thrown down” in Mk. 13:2 (and his apocalypticism in general), since Dan. 9:26 goes on to say:Now after the sixty-two weeks, an anointed one will be cut off and have nothing.
As for the city and the sanctuary, the people of the coming prince will destroy them. But his end will come speedily like a flood. Until the end of the war that has been decreed there will be destruction.
I think this conflation of "the Messiah" and Daniel's "son of man" is also apparent in Mk. 14:61-62:
And I think this is why Jesus was a false prophet (at least from the perspective of the Torah), because he made this prediction that "you will see the Son of Man sitting at the right hand of Power and coming with the clouds of heaven" (echoed in Mk. 9:1: "And he said to them, "Truly I tell you, some who are standing here will not taste death before they see that the kingdom of God has come with power"; and in 13:26-27: "At that time people will see the Son of Man coming in clouds with great power and glory. And he will send his angels and gather his elect from the four winds, from the ends of the earth to the ends of the heavens"), and I don't think this ever happened (to judge from Christians themselves!).Again the high priest questioned Him, “Are You the Christ, the Son of the Blessed One?” “I am, said Jesus, “and you will see the Son of Man sitting at the right hand of Power and coming with the clouds of heaven.”
I once considered something Josephus says in War 6.5.3 in light of Jesus' prediction, that one of the signs seen before the destruction of 70 CE was that:
Hey, maybe this was Jesus and his angels. Maybe Jesus was right. But as I said, Christians themselves don't seem to think that the Messiah/"son of man" has come on the clouds of heaven yet. In late first century CE to mid second century CE Jewish Christian writings (Revelation, Hegesippus) it hasn't happened yet. In Hegesippus, for example, the grandsons of Jesus' brother Judas are said to still be waiting up to the time of Trajan:...a certain prodigious and incredible phenomenon appeared; I suppose the account of it would seem to be a fable, were it not related by those that saw it, and were not the events that followed it of so considerable a nature as to deserve such signals; for, before sun-setting, chariots and troops of soldiers in their armour were seen running about among the clouds, and surrounding of cities.
And when they were asked concerning Christ and his kingdom, of what sort it was and where and when it was to appear, they answered that it was not a temporal nor an earthly kingdom, but a heavenly and angelic one, which would appear at the end of the world, when he should come in glory to judge the quick and the dead, and to give unto every one according to his works. Upon hearing this, Domitian did not pass judgment against them, but, despising them as of no account, he let them go, and by a decree put a stop to the persecution of the Church. But when they were released they ruled the churches because they were witnesses and were also relatives of the Lord. And peace being established, they lived until the time of Trajan.