Faldage's reply
Yes, translation correct. This supposedly became a conjuration or part of a charm with medieval "magicians" because these were words of power. According to Roman Catholic teaching, at the moment a duly-ordained priest utters these words during the Mass, having the Host (a special large-sized communion wafer, or other piece of bread) in his hands, the bread is changed from a mere piece of bread to the actual and true body of Jesus Christ. There are regulations as to how this part of the Mass is to be performed; e.g., it is required that the words be spoken all in one breath.