St. Casimir died at the age of 23 in 1484 from lung disease. He was buried with his favorite song, a Latin hymn to Mary called “Omni die dic Mariae” which we know as “Daily, Daily Sing to Mary.” Because of his love for the song, it is known as the Hymn of St. Casimir though he didn’t write it.

A copy of this hymn by Bernard of Cluny was found beneath the right temple of St. Casimir’s incorrupt body when his grave was opened.

Prayer:

Daily, daily sing to Mary, Sing, my soul, her praises due: All her feasts, her actions honor With the heart’s devotion true.
Lost in wond’ring contemplation, Be her majesty confessed: Call her Mother, call her Virgin, Happy Mother, Virgin blest.
2 She is mighty in her pleading, Tender in her loving care; Ever watchful, understanding, All our sorrows she will share.
Advocate and loving mother, Mediatrix of all grace: Heaven’s blessings she dispenses On our sinful human race.
3 All our graces flow through Mary; All then join her praise to sing: Fairest work of all creation, Mother of creation’s King.
Sing in songs of peace unending, Call upon her lovingly: Seat of wisdom, Gate of heaven, Morning star upon the sea.