Ambrose of Milan
Catena Aurea · Lukasevangelium 1
And the angel said unto her, Fear not, Mary: for thou hast found favour with God. And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS. He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end. When the angel saw that she was troubled at this unusual salutation, calling her by her name as if she was well known to him, he tells her she must not fear, as it follows; And the angel said, Fear not, Mary.
It was said also of John, that he shall be great, but of him indeed as of a great man, of Christ, as of the great God. For abundantly is poured forth the power of God; widely the greatness of the heavenly substance extended, neither confined by place, nor grasped by thought; neither determined by calculation, nor altered by age.