16 Was it without reason that Christ was made Man? Are our teachings ingenious phrases and human subtleties? Are not the Holy Scriptures our salvation? Are not the predictions of the Prophets? Keep then, I pray you, this deposit undisturbed, and let none remove you: believe that God became Man. But though it has been proved possible for Him to be made Man, yet if the Jews still disbelieve, let us hold this forth to them: What strange thing do we announce in saying that God was made Man, when yourselves say that Abraham received the Lord as a guest?
What strange thing do we announce, when Jacob says, For I have seen God face to face, and my life is preserved? The Lord, who ate with Abraham, ate also with us. What strange thing then do we announce? Nay more, we produce two witnesses, those who stood before Lord on Mount Sinai: Moses was in a cleft of the rock, and Elias was once in a cleft of the rock: they being present with Him at His Transfiguration on Mount Tabor, spoke to the Disciples of His decease which fire should accomplish at Jerusalem. But, as I said before, it has been proved possible for Him to be made man: and the rest of the proofs may be left for the studious to collect.
Source: Catechetical Lectures (New Advent)