John Chrysostom — as excerpted in the Catena Aurea on John 3:32-36

“(Hom. xxx. 2) By Spirit here is meant the operation of the Holy Spirit. He wishes to shew that all of us have received the operation of the Spirit by measure, but that Christ contains within Himself the whole operation of the Spirit. How then shall He be suspected, Who saith nothing, but what is from God, and the Spirit? For He makes no mention yet of God the Word, but rests His doctrine on the authority of the Father and the Spirit. For men knew that there was God, and knew that there was the Spirit, (although they had not right belief about His nature;) but that there was the Son they did not know.”