They didn’t know what he meant. The meaning was hidden from them so that they didn’t understand it. Besides, they were afraid to ask him about what he had said.
At first Jesus’ disciples didn’t know what these prophecies meant. However, when Jesus was glorified, the disciples remembered that these prophecies had been written about him. The disciples remembered that they had taken part in fulfilling the prophecies.
The crowd responded to him, “We have heard from the Scriptures that the Messiah will remain here forever. So how can you say, ‘The Son of Man must be lifted up from the earth’? Who is this ‘Son of Man’?”