John Calvin Commentary John 4:2

"(although Jesus himself baptized not, but his disciples)," — John 4:2 (ASV)

Though Jesus himself baptized not. He gives the designation of Christ’s Baptism to that which he conferred by the hands of others, to inform us that Baptism should not be estimated by the person of the minister, but that its power depends entirely on its Author, in whose name, and by whose authority, it is conferred.

Therefore, we derive a remarkable consolation when we know that our baptism has no less efficacy to wash and renew us than if it had been given by the hand of the Son of God. Nor can it be doubted that, as long as he lived in the world, he abstained from the outward administration of the sign for the express purpose of testifying to all ages, that Baptism loses nothing of its value when it is administered by a mortal man.

In short, not only does Christ baptize inwardly by his Spirit, but the very symbol we receive from a mortal man should be viewed by us in the same light as if Christ himself displayed his hand from heaven and stretched it out to us. Now, if the Baptism administered by a man is Christ’s Baptism, it will not cease to be Christ’s Baptism whoever the minister is. And this is sufficient for refuting the Anabaptists, who maintain that when the minister is a wicked man, the baptism is also vitiated, and, through this absurdity, disturb the Church, just as Augustine very properly employed the same argument against the Donatists.