From On the Errors of the Trinity book 6:
You will (if you have examined your capacity with the sober judgment of reason) easily recognize the knowledge of God which we obtain through CHRIST. For in himself God is incomprehensible; he can be neither imagined, nor understood, nor discovered by thinking, unless you contemplate some aspect in him. And the likeness of Christ and the Person of the Word are just this. For the impersonated oracle of God, the Person of Christ, as I have said above, which was with God, was God himself; nor was there in him any other aspect than that.
From On the Errors of the Trinity book 7:
With regards to filiation among divine beings, and the divinity of CHRIST, and hypostasis of the Word, questions are usually asked which I shall clear with a few words. I say that from the beginning there was among the divine beings a filiation, not real but personal. The Son was the Word; the Son was not real but personal, in so far as it was the Person of CHRIST. Nor is he in Scripture ever called Son, but an eternal kind of generation is attributed to CHRIST, and the things that were in the law were a shadow of the body of Christ. Yet some dream here of an emanation of a conception, or a Word, from the divine mind, by means of an emanating filiation…
But in God, within, there are no goings forth, nor emanations; but CHRIST was formed beforehand in the divine mind. There was a certain way of keeping himself which God arranged in himself in order that he might manifest himself to us; namely, by representing in himself the likeness of JESUS CHRIST, for all this was foreordained for exhibiting the glory of CHRIST. And John did not say that the Word emanated from God, but it was in God, the Word was God.