Therefore when the Lord knew that the Pharisees had heard that Jesus was making and baptizing more disciples than John
The disciples of John the Baptist were already jealous of Jesus' success; and the Lord knew that the mighty acclaim hailing his efforts, if uninterrupted, would shortly bring upon him a premature confrontation with the Pharisees; and, in order to avoid it, he promptly switched the scene of his labors.  The inference here is that if relatively friendly persons such as John's disciples were actively jealous of Jesus, the far more antagonistic Pharisees would be likely to take drastic action.  Not long after these events, the Pharisees accomplished the destruction of John the Baptist; and, although their hand is hidden in the sacred account of his martyrdom, it is very likely that those wily hypocrites of the priestly hierarchy had maneuvered John into making the comment on Herod's unlawful marriage which resulted in his execution.  The Lord, in time, planned to die for the salvation of all men; but, at that particular time, his hour had not yet come.