The saint (Peter Damien) illustrates this by comparing the unity of Christ in His Mystical Body with His unity in His sacramental Body. Just as on all the altars of the world there is but one Body of Christ and One chalice of His Precious Blood, so the whole Christ is present in each individual member of the Church. It is by virtue of these principles that St. Peter Damian shows how the hermit priest, reciting the office alone in his mountain oratory, can and indeed must say “Dominus vobiscum” and answer himself “Et cum spiritu tuo.” The whole Church is present in the cell where he is alone.
Thomas Merton. The Silent Life. Farrar, Straus, and Giroux, New York (1957) p. 151.