THE VIRTUES OF MARY: The story we just heard shows forth especially Mary's faith, chastity, and humility. Firstly, the angel announced to her something stupendous, namely, that God was about to become Man, and that she, without losing her virginity, was to be His Mother: and Mary confidently believed what was told her. Secondly, she had made a vow of virginity, in the full persuasion that the state of virginity was a far higher one and far more pleasing to God than that of maternity. This being perfectly true, God combined the two in her case and gave her the glory of both states. Lastly, her humility has been shown forth. She was troubled by the angel's respectful manner of salutation, and, in spite of all he had said, she still called herself the handmaid of the Lord. "God resisteth the proud and giveth grace to the humble." (James 4:6.) Mary, in real humility, abased herself; therefore God raised her to the highest dignity.
[From 'A Practical Commentary on Holy Scripture' by Bishop Knecht, D.D.] (1899 Douay-Rheims Bible)