"Ave verum corpus" is a short Eucharistic hymn that has been set to music by various composers. It dates from the 14th century and has been attributed to Pope Innocent VI.

Lyrics

Ave verum corpus, natum
de Maria Virgine,
vere passum, immolatum
in cruce pro homine
cuius latus perforatum
fluxit aqua et sanguine:
esto nobis praegustatum
in mortis examine

O Iesu dulcis, O Iesu pie,
O Iesu, fili Mariae.
Miserere mei. Amen

Translation:

Hail, true Body, born
of the Virgin Mary,
having truly suffered, sacrificed
on the cross for mankind,
from whose pierced side
water and blood flowed:
Be for us a foretaste [of the Heavenly banquet]
in the trial of death!

O sweet Jesus, O holy Jesus,
O Jesus, son of Mary,
have mercy on me. Amen.