What does Matthew 14:10 mean?

Jesus said this to a crowd about His relative John the Baptist: "For all the Prophets and the Law prophesied until John, and if you are willing to accept it, he is Elijah who is to come" (Matthew 11:13–14). There's no doubt that John was God's man sent to deliver God's message at God's time. He was the one commissioned to prepare the way for the Messiah, and he had done exactly that.

Now John is killed in the least dignified of ways for calling out the sin of one of Israel's rulers. Herod Antipas orders John to be beheaded in the prison that is likely inside his own fortress, on the very night and at the very place where Herod is holding a birthday party for himself. Herod has been cornered into this sudden execution by an impulsive promise made to the teenage daughter of his wife in front of his guests (Matthew 14:1–9; Mark 6:19–29).

Jewish law required a prisoner to receive a trial before execution. Scholars debate the extent to which beheading was meant to be used as a punishment. In multiple ways, Herod rejected God's authority over him and over Israel.