Not to tell
καὶ ἐπετίμησεν αὐτοῖς ἵνα μηδενὶ λέγωσιν περὶ αὐτοῦ.
This warning about the messianic secret can be found in all 3 synoptic gospels, Matthew, chapter 16:20, Luke, chapter 9:21, and here. However, this warning came right after Peter’s response in Mark and Luke, since they did not have the unique Matthew reward for Peter. Jesus, in some ironic way, did not want the people to know that he was the Messiah or the Christ. Thus, the name “Jesus Christ” did not take hold until after his death and resurrection. Mark said that Jesus sternly ordered, instructed, or charged his disciples (καὶ ἐπετίμησεν αὐτοῖς) that they were not to tell anyone about Jesus (ἵνα μηδενὶ λέγωσιν περὶ αὐτοῦ) that he was the Christ or the Israelite Messiah. Only the elite followers of Jesus knew that he was the Christ messiah, much like a gnostic special knowledge.