In Matthew 16:20, Jesus tells them not to tell anyone who he is because they do not fully understand what it means that Jesus is the Messiah. Peter’s reaction to his prohibition (see Matthew 16:22) shows that they still do not understand that the Messiah had to suffer. Since the Jews had political expectations for the Messiah, and Jesus had not yet died and risen, the disciples were not ready to publicly declare that he was the Christ, so Jesus told them not to speak about it (see Mark 8:30).
Jesus is about to reveal to his disciples that rejection will be an essential part of his mission, all the way up to death (Matthew 16:21), so he starts preparing his disciples for the path that leads to the cross (Matthew 16:21–28). As he will remain silent before his judges and endure their hostility, so the disciples must now remain silent in the face of the hostility of those who deny Jesus. The meaning of this specific, strictly time-bound command is clear from the instructions Jesus gives right afterward (Matthew 16:21–28).
In Matthew 16:20, Jesus prohibits the disciples from telling anyone who he is because before they could proclaim that Jesus was the Messiah, they first had to understand what that meant. Peter’s reaction to this prohibition (see Matthew 16:22) shows that at that moment they still did not understand that the Messiah had to suffer. Since the Jews associated the messianic title with many extraordinary political expectations, and since Jesus had not yet died and risen, the time was not yet ripe for a public proclamation that he was the Christ. Jesus therefore strictly commanded them not to speak about it (see Mark 8:30).1
Jesus is about to reveal to his disciples that rejection would be an essential part of his mission, and that he would have to bear this rejection unto death himself (Matthew 16:21). The Master therefore here starts to prepare his disciples for the path that leads to the cross (Matthew 16:21–28). Just as the Saviour will remain silent before his judges and endure their hostility, so too must the disciples now remain silent among those who do not believe. They may not protest, but from this point on they must endure the reality that many will deny Jesus and refuse to honour him as the Christ. They must quietly suffer the public denial of others, even while they themselves quietly confess him. The meaning of this specific, strictly time-bound command becomes evident from the instructions Jesus gives immediately afterward (Matthew 16:21–28).2
20 Alors il recommanda aux disciples de ne dire à personne qu'il était le Christ.