(The antiphon for the magnificat for first vespers, according to the revised Liturgy of the Hours)
The Assumption of the Blessed Virgin is my favourite feast of the entire year. It was the day I got my father's permission to go to RCIA, after a novena. It was the day I first started singing the divine office using Gregorian chant. It the feast of hope for all Christians, who hope for the joy of the resurrection of the body at the last day, for Mary was the first of redeemed humanity to take part in it.
It also has one of my favourite offices. Whether one uses the Roman Breviary or the Liturgy of the Hours, the office of the feast has the texts of the second oldest Marian office in the breviary. (The first being that of Mary, the Holy Mother of God on the octave of Christmas.) In the new breviary, which is what I use for the daily office, the texts of the antiphons are taken from a 14th century French breviary, and both textually and musically, they're quite beautiful. This will be my third time going through the sung office, and for the third year in a row, I'll be using new antiphons. For my first year, I used all the antiphons from the old office, as that was all I had. Last year, I used the texts as in the breviary, set to the chants from the Liber Usualis. This year,I'll be using the right antiphons: Those stipulated to be used in the Ordo Cantus Officii.
Unfortunately, in going through them, I saw an unfortunate trend in the texts of the new breviary: The texts in the breviary are shortened forms of the actual antiphons. Compare that antiphon (Of which the first sentence is missing) to the comparative antiphon used in the Liturgia Horarum:
"Ascéndit Christus super cælos, et præparávit suæ castíssimæ Matri immortalitátis locum, allelúia."
You can see, they only used One Sentence out of the whole antiphon! It creates a silly discrepancy between those who recite the office and those of us who sing it. I hope some day this will be resolved.