‘Now Herod the tetrarch heard of all that was done, and he was greatly perplexed, because it was said by some, that John was risen from the dead, and by some, that Elijah had appeared, and by others, that one of the old prophets was risen again.'
The news of these activities inevitably reached Herod through his spies, and it had also become a talking point everywhere. He was very perplexed because of the rumours that were spreading about. Some were saying that his old adversary John the Baptiser was risen from the dead, possibly seeing it as a vindication of John and looking venomously at Herod. Others declared confidently that Elijah had appeared. Elijah was very much an expected figure on the basis of Malachi 4:5. Still others said that it was one of the other prophets (compare Matthew 16:14). The return of Isaiah and Jeremiah is anticipated in extra-Biblical Jewish literature, for example in Esther 2:18; Esther 2:18, suggesting that this was a part of Jewish tradition. Note the neat distinction between those who had been raised, and Elijah, who had never died but had simply been taken up into Heaven. This is all preparing us for Luke 9:19-20. It also lets us know what kind of questions the Apostles would have to face on their mission.
This is the first notice that we have in Luke of the fact that John is dead. The next verse will tell us how he died.