Oracle of the Holy Bottle, Bacbuc
near Cathay, in Upper Egypt. Books iv. and v. of Rabelais are occupied by the search for this oracle. The ostensible object was to obtain an answer to a question which had been put to sibyl and poet, monk and fool, philosopher and witch, judge and “sort,” viz. “whether Panurge should marry or not?” The whole affair is a disguised satire on the Church. The celibacy of the clergy was for a long time a moot point of great difficulty, and the “Holy Bottle” or cup to the laity was one of the moving causes of the “great schisms” from the Roman Catholic Church. The crew setting sail for the Bottle refers to Anthony, Duke of Vendôme, afterwards king of Navarre, setting out in search of religious truth. Bacbuc is the Hebrew for a bottle. The anthem sung before the fleet set sail was When Israel went out of bondage, and all the emblems of the ships bore upon the proverb “In vino veritas.” Bacbuc is both the Bottle and the priestess of the Bottle.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894