Thou art the true and living Bread, thou that didst descend from heaven to give food to them that hunger, yea, to be thyself the food of them that live.
Thou gives thyself in that Bread wherewith hearts are made strong, that by virtue of this Bread we may have strength to fast throughout these days that are dedicated to thy Name, without fainting of flesh and blood, being fed by thee: for thou feedest thy poor ones abundantly with heavenly loaves.
Thou didst make the number forty a mark for Moses and Elijah, who continued in fasting for forty days. Thereafter even thyself, fasting, thou didst mark for us the same number of days of solemn fast.
Therefore what thou thyself in the weakness of our flesh didst fulfillment through forty days and nights, let us fulfill in due order throughout the same number of days; and end each separate reckoning with our evening prayer.
from The Mozarabic Missal
Eucharistic Prayers from the Ancient Liturgies
Chosen and Arranged by Evelyn Underhill
Longmans, Green and Co.