The unchangeable God follows, so to speak, His own nature, by begetting unchangeable God. Nor does the perfect birth of unchangeable God from unchangeable God forsake His own nature. We understand then here the nature of God subsisting in Him, since God is in God, nor besides Him who is God, can any other be God.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: v. de Trin