The crowds were amazed at Jesus, because he taught with his own authority.

Matthew 7:28-29

28 When Jesus finished saying all those things, the crowdswho had been listening to him were amazed at the new teaching that he had taught them. 29 The reason they were amazed was that he was teaching as a person does who has authority. He was not teaching like the men who taught the Jewish laws, who just repeated what other people had taught them.