the magnificat is the song of Mary, after she goes to meet her cousin Elizabeth. Mary is pregnant with Jesus and Elizabeth with John, and the John (older by six months) leaps in Elizabeth's womb at the approach of Mary. Mary responds by singing this song. it is found at luke 1:46–55 in the bible.

this canticle has a special place in evening prayers.

my soul proclaims the greatness of the Lord,
my spirit rejoices in God my Savior;
    for he has looked with favor on his lowly servant.
from this day all generations will call me blessed:
    the Almighty has done great things for me,
    and holy is his Name.
he has mercy on those who fear him
    in every generation.
he has shown the strength of his arm,
    he has scattered the proud in their conceit.
he has cast down the mighty from their thrones,
    and has lifted up the lowly.
he has filled the hungry with good things,
    and the rich he has sent away empty.
he has come to the help of his servant Israel,
    for he has remembered his promise of mercy,
the promise he made to our fathers,
    to Abraham and his children for ever.