Albert Barnes Commentary Matthew 14:2

"and said unto his servants, This is John the Baptist; he is risen from the dead; and therefore do these powers work in him." — Matthew 14:2 (ASV)

This is John the Baptist. Herod feared John. His conscience struck him for his crimes. He remembered that he had wickedly put him to death. He knew him to be a distinguished prophet; and he concluded that no one else was capable of working such miracles except he who had been distinguished in his life, and who had again risen from the dead and entered the dominions of his murderer.

The alarm in his court, it seems, was general. Herod's conscience told him that this was John. Others thought that it might be the expected Elijah, or one of the old prophets (Mark 6:15).