E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Hocus Pocus.
The words uttered by a conjuror when he performs a trick, to cheat or take surreptitiously. The Welsh, hocea pwca (a goblins trick, our hoax) is a probable etymology. But generally supposed to be Hoc est oorpus.
1
Ochus Bochus was the name of a famous magician of the North invoked by jugglers. He is mentioned in the French Royal Dictionary.