Jesus often referred to himself as the Son of Man, a title he took from this very chapter. In chapter seven, Daniel wrote about a dream he had of beastly kingdoms and the hopeful future of a perfect human finally taking his rightful place as King over all creation on the throne with the Most High God.
Here Comes the Son of Man
Chapter 21 of Luke shows us Jesus at the temple in Jerusalem, the week of his death. Everyone he is with is enamored with the beauty of the temple, but Jesus is not impressed. He is more concerned with what is going on inside of the temple and inside of the hearts of the people within it. He is more concerned with creating a new temple for him to dwell in. He is more concerned with establishing a kingdom and a throne that will last forever.