Albert Barnes Commentary John 4:1

"When therefore the Lord knew that the Pharisees had heard that Jesus was making and baptizing more disciples than John" — John 4:1 (ASV)

The Lord knew. When Jesus knew. How he knew this we are not informed; whether by that power of omniscience by which he knew all things, or whether some person had informed him of it.

How the Pharisees had heard. The Pharisees, here, seem to denote either the members of the Sanhedrin or those who were in authority. They claimed the authority to regulate the rites and ceremonies of religion, and hence they supposed they had a right to inquire into the conduct of both John and our Lord. They had on a former occasion sent to inquire of John by what authority he had introduced such a rite into the religion of the Jewish people .

More disciples than John. Though many of the Pharisees came to his baptism (Matthew 3), yet those who were in authority were displeased with the success of John (John 1:25). The reasons for this were, probably, the severity and justice of his reproofs (Matthew 3:7), and the fact that by drawing many after him he weakened their authority and influence. As they were displeased with John, so they were with Jesus, who was doing the same thing on a larger scale—not only making disciples, but baptizing also without their authority, and drawing away the people after him.