St. Gregory of Nazianzus: "Begotten of the Father"

"BELIEVE that the Son of God, the Eternal Word, Who was begotten of the Father before all time and without body, was in these latter days for your sake made also Son of Man, born of the Virgin Mary ineffably and stainlessly (for nothing can be stained where God is, and by which salvation comes), in His own Person at once entire Man and perfect God."

~St. Gregory of Nazianzus (c. 325 - 389): Orations, 40, 45.

Nativity, by Domenico Ghirlandaio. 

Tempera on panel, c. 1492; Fitzwilliam Museum, Cambridge.