This little sidelight in the midst of the story of the journey of the twelve might seem oddly placed. Perhaps understanding a little more about Herod will help us see the importance of its inclusion.
Herod the Great was the ruler of Judea at the time Jesus was born. It was to Herod the Great that the magi went seeking the infant King, and it was this madman, Herod the Great, who slaughtered infants throughout Judea in an effort to eliminate the presumed infant threat to his throne. He was a visionary in construction and building, and the Temple Mount, breathtaking in its expanse, was one of his projects. He, who executed numerous relatives including his own wife, claimed to be a Jew.
Herod the Great's son, Herod Antipas, was born to Malthace, a Samaritan woman who was one of his five wives. Herod Antipas served as Tetrarch over Galilee and Perea. Like his father, he was also a great builder and Tiberius was one of the projects he completed. Also like his father, he had a lavish (and corrupt) lifestyle. It was this Herod Antipas who married his half-brother's wife Herodias and was condemned by John the Baptizer for the marriage. Herod Antipas, after arresting and imprisoning him, was manipulated into executing John at the behest of Herodias.
As the twelve journeyed throughout Galilee, they preached and healed, lives were changed, and the news spread. What is remarkable is that the news of Jesus and the twelve traveled all the way to Herod Antipas. Herod heard about this itenerate preacher and his band of traveling apprentices and wondered what it all meant. "What are people saying about them?" He must've asked. His sources told him that some people thought Jesus was really Elijah or one of the other prophets.
They must have shuddered as they told him the rest of the news. There were some people who thought that Jesus was actually John the Baptizer, risen from the dead. That news gave Herod Antipas a shudder of his own. Scripture says he was "greatly perplexed". The word here is diaporeō,