The Psalm says: His going forth is from the height of heaven, and His return unto its height (Ps. 18:7). Now no one returns except to where he was; but when Christ ascended, the Son of man returned into heaven, He who was before in heaven. So too holy Paul, expounding, says: Ascending on high, He led captivity captive, He gave gifts to men (Eph. 4:8-9). And a little after: He who descended, he says, is the same also who ascended above all the heavens, that He might fill all things. And although throughout every passage of his discourse he proclaims that God came, concluding that the man returned, here nevertheless he says that the same one ascends who descended; because in Christ there is God and man — not another, but the same; not two from diverse [natures], but the same mediator from both.
143:2
Geminaquidemsubstantia, sedunaformaest.
本體固然是雙重的，但形式卻是同一個。
The substance indeed is twofold, but the form is one.