Matthew 14:5

When he would have put him to death] This agrees with Josephus, who says that John was arrested for political reasons. 'Herod, who feared lest the great influence John had over the people might put it into his power and inclination to raise a rebellion, thought it best by putting him to death to prevent any mischief that he might cause.' St. Mark, on the other hand, represents Herod as friendly to John. 'Herod feared John, knowing him to be a just and holy roan, and he kept him safe. And when he heard him, he was much perplexed and heard him gladly.'

The truth seems to be that Herod was really friendly to John, and favourably impressed by his preaching, but that John's denunciation of his new marriage rendered it difficult for that prince to protect him. He therefore yielded, though reluctantly, to the influence of Herodias, and first had John arrested, and then executed. But since it would have been impolitic to disclose the true reason of these proceedings, it was given out that John was suspected of treasonable practices.