The 1962 and earlier forms of the Roman Canon included among the words attributed to Jesus in connection with the consecration of the chalice the phrase ""mysterium fidei"". It has been suggested that this was an anti-Manichaean addition by Pope Leo the Great (440-461), insisting on the goodness of material things: the material blood of Christ and the material elements used in the Eucharist. Another proposed explanation is that originally the phrase was not spoken by the priest but was a calling to attention by the deacon.