He then gives a notable explanation of the saying of the Lord to Philip, He that has seen Me has seen the Father; and herein he excellently discusses the suffering of the Lord in His loveto man, and the impassibility, creative power, and providence of the Father, and the composite nature of men, and their resolution into the elements of which they were composed
Sufficient defence has been offered on these points, and as for that which Eunomius says by way of calumny against our doctrine, that “Christ was emptied to become Himself” there has been sufficient discussion in what has been said above, where he has been shown to be attributing to our doctrine his own blasphemy. For it is not one who confesses that the immutable Nature has put on the created and perishable, who speaks of the transition from like to like, but one who conceives that there is no change from the majesty of Nature to that which is more lowly.
For if, as their doctrine asserts, He is created, and man is created also, the wonder of the doctrine disappears, and there is nothing marvellous in what is alleged, since the created nature comes to be in itself. But we who have learned from prophecy of “the change of the right hand of the Most High,”— and by the “Right Hand” of the Father we understand that Power of God, which made all things, which is the Lord (not in the sense of depending upon Him as a part upon a whole, but as being indeed from Him, and yet contemplated in individual existence)—say thus: that neither does the Right Hand vary from Him Whose Right Hand It is, in regard to the idea of Its Nature, nor can any other change in It be spoken of besides the dispensation of the Flesh.
For verily the Right Hand of God was God Himself; manifested in the flesh, seen through that same flesh by those whose sight was clear; as He did the work of the Father, being, both in fact and in thought, the Right Hand of God, yet being changed, in respect of the veil of the flesh by which He was surrounded, as regarded that which was seen, from that which He was by Nature, as a subject of contemplation. Therefore He says to Philip, who was gazing only at that which was changed, “Look through that which is changed to that which is unchangeable, and if you see this, you have seen that Father Himself, Whom you seek to see; for he that has seen Me— not Him Who appears in a state of change, but My very self, Who am in the Father— will have seen that Father Himself in Whom I am, because the very same character of Godhead is beheld in both.”
If, then, we believe that the immortal and impassible and uncreated Nature came to be in the passible Nature of the creature, and conceive the “change” to consist in this, on what grounds are we charged with saying that He “was emptied to become Himself,” by those who keep prating their own statements about our doctrines? For the participation of the created with the created is no “change of the Right Hand.” To say that the Right Hand of the uncreated Nature is created belongs to Eunomius alone, and to those who adopt such opinions as he holds.
For the man with an eye that looks on the truth will discern the Right Hand of the Highest to be such as he sees the Highest to be—Uncreated of Uncreated, Good of Good, Eternal of Eternal without prejudice to Its eternity by Its being in the Father by way of generation. Thus our accuser has unawares been employing against us reproaches that properly fall upon himself.
Source: Against Eunomius (New Advent)