Date uncertain; found at the end of the life of Saint Brendan, Paris MS 2333 A. Colbert (14th Century). English translation by Karen Rae Keck, 1994.
COLLECT: O God, Who hast offered us today this most holy day, the feast of thy confessor and abbot the blessed Brendan, uphold Thy Church by his holy prayers, that he whose merits are secured may glory in Thy mercies.
SAID BY THE PRIEST SILENTLY: On the holy altars, O Lord, where sacrifices are place, let holy Abbot Brendan beseech our Lord that He may come to us in good will.
POST-COMMUNION PRAYER: Let the Blessed Abbot Brendan shield us, O Lord, with the understanding of Thy sacrament, interceding for us that we may know the sign of his holy life, and may know the mercies of his intercession.