Ambrose of Milan
Catena Aurea · Lukasevangelium 1
And, behold, thy cousin Elisabeth, she hath also conceived a son in her old age: and this is the sixth month with her, who was called barren. For with God nothing shall be impossible. And Mary said, Behold the handmaid of the Lord; be it unto me according to thy word. And the angel departed from her.
Behold now the humility, the devotion of the virgin. For it follows, But Mary said, Behold the handmaid of the Lord. She calls herself His handmaid, who is chosen to be His mother, so far was she from being exalted by the sudden promise. At the same time also by calling herself handmaid, she claimed to herself in no other way the prerogative of such great grace than that she might do what was commanded her. For about to bring forth One meek and lowly, she was bound herself to shew forth lowliness. As it follows, Be it unto me according to thy word. You have her submission, you see her wish. Behold the handmaid of the Lord, signifies the readiness of duty. Be it unto me according to thy word, the conception of the wish.