The Visitation in the Book of Hours of the Duc de Berry
The Magnificat is the song that the Virgin Mary sang after Elizabeth told her that she is going to give birth to God's son. This is the story told in the Bible in the book of Luke Chapter 1, verses 46-55. It is also known as the Song of Mary. "Magnificat" is a Latin word meaning "magnifies" (saying how great [God] is).