Whereas he had said, the Word was God, the fearfulness, and strangeness of the speech disturbed me; the prophets having declared that God was One. But, to quiet my apprehensions, the fisherman reveals the scheme of this so great mystery, and refers all to one, without dishonour, without obliterating [the Person], without reference to timeb, saying, The Same was in the beginning with God; with One Unbegotten God, from whom He is, the One Only-begotten God.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: ii. de Trin. c. 16