See the notes at Matthew 20:17-19.
By the prophets - Those who foretold the coming of the Messiah, and whose predictions are recorded in the Old Testament.
Son of man - The Messiah. They predicted that certain things would take place respecting the Messiah that was to come. See the Daniel 9:25-27 notes; Isaiah 53 notes. “These things,” Jesus said, would be accomplished “in him,” he being the Son of man, or the Messiah.