Mark 6:17-18

17Herod himself had sent his soldiers to take hold of John. He had said to his soldiers, ‘Tie his hands and feet and put him in prison.’ Herod had done that because of his wife, Herodias. She had been the wife of Herod's brother, Philip. But Herod had married her.

18John had said to him, ‘Herodias is your brother's wife. It is not right for you to have her as your wife.’