In Malory's version of the quest for the grail, the grail is closely identified with Christ, although it is not the "cup Christ bled into":

Than loked they and saw a man com oute of the holy vessell that had all the sygnes of the Passion of Jesu Cryste bledynge all opynly [....] "Thys ys," seyde He," the holdy dysshe wherein I ete the lambe on Estir Day, and now hast thow sene that thou moste desire to se."
Selections from Thomas Malory's Morte d'Arthur. Edited by Eugene Vinaver.