While everyone was amazed at all that Jesus was doing, he said to his disciples, ‘Let these words sink into your ears: The Son of Man is going to be betrayed into human hands.’ But they did not understand this saying; its meaning was concealed from them, so that they could not perceive it. And they were afraid to ask him about this saying.
(Lectionary, New Revised Standard Version)
Our reading today comes after a busy period in Jesus' life. In Chapter 9 of Luke's Gospel we see all of the following happen before the words in the passage, above:
Jesus has already foretold his own death and resurrection (Luke 9.21-27), and now he repeats the warning - he is to be betrayed into the hands of his enemies. There can only be one ending with the Romans in control. Neither can there be any doubt about the title "Son of Man". At the end of this chapter Jesus says "The Son of Man came to save lives," (9.56) and "The Son of Man has nowhere to lay his head," (9.58). This title is the one used by Jesus more than any other. It is a sign of his humility, that the Son of God should leave His glory to take on flesh as a member of a subject nation, to be despised, ridiculed, convicted and to die on a cross for God's people.
So why do the disciples hear, but not understand Jesus' words? Well they are on a high and don't want to hear the reality that the Messiah is to die at the hands of evil people. But this is God's plan to rescue His people. Someone must be punished for our sin, and Jesus chooses to accept that sacrifice voluntarily, as an act of love. The disciples hear, but are not yet ready to understand the truth. How different are we?
Lord God,
we know that ours is a sinful world
that is fractured and broken
because of human weakness
and human wilfulness.
We try to forget that one man,
Your Son, Jesus Christ,
freely chose to pay the price for our sin,
and that when we had wandered away
He brought us back.
Help us to be worthy of such sacrifice,
and live the life You would have us live.
Amen.
If you would to look further at why Luke sees Jesus as the Son of Man, this article is good: