If Christ be God, not begotten, but unbegotten, then let this receiving be thought weakness. But not if His receiving of power signifies His begetting, in which He received what He is. This gift cannot be counted for weakness. For the Father is such in that He gives; the Son remains God in that He hath received the power of giving eternal life.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: ix. de Trin. 31