Albert Barnes Commentary Matthew 16:20

"Then charged he the disciples that they should tell no man that he was the Christ." — Matthew 16:20 (ASV)

Then charged, etc. This means he then commanded them. Mark 8:30 and Luke 9:21 (Greek) state that he strictly or severely charged them. He laid emphasis on it, as a matter of much importance.

The reason for this seems to be that his time had not fully come; he was not willing to rouse Jewish malice and endanger his life by having it proclaimed that he was the Messiah.

The word "Jesus" is missing in many manuscripts and should probably be omitted. Then he charged them strictly to tell no man that he was the Christ or Messiah.