Why are these 2 from Luke always in the LOTH? They are wonderful, but why so important to be said every day?
Don’t forget the third, the Nunc Dimittis, also from Luke, said everyday at Night Prayer.
The Canticle of Zechariah is said every morning because it celebrates the coming of the Light, which is one of the symbolisms of the sunrise.
The Canticle of Mary is said in the evening because it praises the mighty deeds God has done, which is suitable for the end of the workday, and so fits well into Evening Prayer’s atmosphere of thanksgiving.
And of course, the Nunc Dimittis is said every night because it reflects the joy of a man at the end of his life, commending himself to God, and as someone said, “What is sleep, if not a small rehearsal for death?” We express that same confidence.
All in all, these three come from the time when Jesus was just an infant, and collectively, they celebrate God’s mercy in giving us our Redeemer.