10 “For He whom God has sent speaks the words of God.” This, of course, he said of Christ, to distinguish himself from Christ. What then? Did not God send John himself? Did he not say himself, “I am sent before Him”? And, “He that sent me to baptize with water”? And is it not of John that it is said, “Behold, I send my messenger before You, and he shall prepare Your way”? Does he not himself speak the words of God, he of whom it is said that he is more than a prophet?
Then, if God sent him too, and he speaks the words of God, how do we understand him to have distinctly said of Christ, “He whom God has sent speaks the words of God”? But see what he adds: “For God gives not the Spirit by measure.” What is this, “For God gives not the Spirit by measure”? We find that God does give the Spirit by measure. Hear the apostle when he says, “According to the measure of the gift of Christ.” To men He gives by measure, to the only Son He gives not by measure.
How does He give to men by measure? “To one is given by the Spirit the word of wisdom; to another the word of wisdom according to the same Spirit; to another faith by the same Spirit; to another prophecy; to another discerning of spirits; to another kinds of tongues; to another the gift of healing. Are all apostles? Are all prophets? Are all teachers? Are all workers of miracles? Have all the gift of healing? Do all speak with tongues? Do all interpret?” This man has one gift, that man another; and what that man has, this has not: there is a measure, a certain division of gifts.
To men, therefore, it is given by measure, and concord among them makes one body. As the hand receives one kind of gift to work, the eye another to see, the ear another to hear, the foot another to walk; nevertheless the soul that does all is one, in the hand to work, in the foot to walk, in the ear to hear, in the eye to see; so are also the gifts of believers diverse, distributed to them as to members, to each according to his proper measure. But Christ, who gives, receives not by measure.
Source: Tractates on the Gospel of John (New Advent)