Augustine of Hippo
Catena Aurea · Johannesevangelium 3
And no man hath ascended up to heaven, but he that came down from heaven, even the Son of man which is in heaven.
(ut sup.) Although He was made the Son of man upon earth, yet His Divinity with which, remaining in heaven, He descended to earth, He hath declared not to disagree with the title of Son of man, as He hath thought His flesh worthy the name of Son of God. For through the Unity of person, by which both substances are one Christ, He walked upon earth, being Son of God; and remained in heaven, being Son of man. And the belief of the greater, involves belief in the less. If then the Divine substance, which is so far more removed from us, and could for our sake take up the substance of man so as to unite them in one person; how much more easily may we believe, that the Saints united with the man Christ, become with Him one Christ; so that while it is true of all, that they ascend by grace, it is at the same time true, that He alone ascends to heaven, Who came down from heaven.