John 4v1

When therefore the Lord knew how the Pharisees had heard that Jesus made and baptized more disciples than John,

This verse is immediately after the previous section, where John the Baptist was telling the priests and Levites sent by the Pharisees about the ministry of Jesus. Here we find the report coming back to the Pharisees, and then Jesus finding out that the Pharisees had heard He is baptising more disciples than John. Jesus seems to react to this information by leaving Judaea for Galilee via Samaria (v3).