Prologue
Many are the wonders of the divine works, as the Psalmist says: wonderful are your works (Ps 137 [138]:14). Yet no work of God is as marvelous as the coming of Christ into the flesh, because, while in his other works God imprinted his likeness on the creature, in the work of the Incarnation he impressed his very self, and united himself to human nature through a unity of person (or united our nature to himself). And hence, while the other works of God are imperfectly knowable, this work (namely, the Incarnation), is entirely without reason. Job 5:9: you do great things and unsearchable, marvelous things without number.
There is one work that I cannot see: if he should come to me, I would not see him (Job 9:11). And in Malachi: behold, the lord of hosts comes, and who can know the day of his coming? (Mal 3:1–2) As though to say: it exceeds the knowledge of man. But the Apostle teaches who would be able to know the day of his coming, saying: not that we are sufficient to think any thing of ourselves, as of ourselves: but all our sufficiency is from God (2 Cor 3:5). Therefore, in the beginning we will ask the Lord that he himself should give me something to say, etc.
Chapter 7 of 50