Matthew 14:4
Because John had been saying to him: it is not lawful for you to have her. John's prophetic charge — it is not lawful — is the application of the Mosaic law to the political ruler. The willingness to tell Herod the truth about his marriage is the courageous consistency of John's ministry: the one who called the religious establishment a brood of vipers (Matthew 3:7) also called the political ruler to account for his violation of the covenant's sexual ethics.