A victim. The consecrated bread of the Eucharist is so called in the Latin Church because it is believed to be a real victim consisting of flesh, blood, and spirit, offered up in sacrifice. (Latin, hostia.) At the service known as the Benediction it is set up for adoration, and with it the blessing is given in a transparent vessel called a “monstrare.” (Latin, monstrare, to show.
Like the leaves of the forest, when summer is green, That host with their banners at sunset was seen; Like the leaves of the forest, when autumn has blown, That host on the morrow lay withered and strown.
Found in few minutes, to his cost, He did but count without his host.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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