Mary’s fiat is found in Lk 1:38. It is her “yes” to God, which she declared once the Angel explained to her that she would conceive a son by the power of the Holy Spirit. Her specific words were, “Behold the handmaid of the Lord: be it done to me according to thy word.” In Latin, it is, "Ecce ancilla Domini; fiat mihi secundum verbum tuum." The Latin word for “be it done” (or “let it be done”) is fiat, so that is the name used by scholars to refer to Mary’s response to the angel.
Mary’s fiat is special because it is through this act of humble submission to the will of God that the Son of God makes his entrance into human history, taking on a human nature and becoming one like us in all things but sin. It is an example to us of obedience and a lively faith in the Lord. Just imagine if all people responded to the will of the Lord by saying, “Let it be done!”
The magnificat, also called the “canticle of Mary,” is the song of praise proclaimed by Mary after Elizabeth rejoiced at Mary coming to visit her. It is from Lk 1:46-55:
- "My soul magnifies the Lord, and my spirit rejoices in God my Savior, for he has regarded the low estate of his handmaiden. For behold, henceforth all generations will call me blessed; for he who is mighty has done great things for me, and holy is his name. And his mercy is on those who fear him from generation to generation. He has shown strength with his arm, he has scattered the proud in the imagination of their hearts, he has put down the mighty from their thrones, and exalted those of low degree; he has filled the hungry with good things, and the rich he has sent empty away. He has helped his servant Israel, in remembrance of his mercy, as he spoke to our fathers, to Abraham and to his posterity for ever."
Most people don’t know what the fiat or the magnificat is because they aren’t familiar with Latin. But, Latin is a revered language that the Church has been using in her worship and her authoritative documents for many centuries. It is good to know at least a few Latin words, at least for the simple purpose of preserving our Catholic traditions and ways of speaking.