Written by St. Thomas Aquinas (1225-1274), this is one of the great seven hymns of the Church. This hymn is also used on the Feast of Corpus Christi. The last two stanzas make up the "Tantum Ergo" (Down in Adoration Falling) that is used at Benediction of the Blessed Sacrament.
O my tongue, its mysteries sing,
And the Blood, all price excelling,
Which the world's eternal King,
In a noble womb once dwelling
Shed for the world's ransoming.
Of a Virgin to proceed,
Man with man in converse blending,
Scattered he the Gospel seed,
Till his sojourn drew to ending,
Which he closed in wondrous deed.
Circled by his brethren's band,
Meekly with the law complying,
First he finished its command
Then, immortal Food supplying,
Gave himself with his own hand.
Very bread his Flesh to be;
Man in wine Christ's Blood partaketh:
And if senses fail to see,
Faith alone the true heart waketh
To behold the mystery.
This great Sacrament revere;
Types and shadows have their ending,
For the newer rite is here;
Faith, our outward sense befriending,
Makes the inward vision clear.
To the Father and the Son;
Honour, might, and praise addressing,
While eternal ages run;
Ever too his love confessing,
Who, from both, with both is one. Amen