Notice the Jesuit Code of Silence Harpocrates gesture.

Harpocrates, derived from the Egyptian Har-pa-khered ("Horus the Child"), holds a significant place in occultism, hermeticism, and ceremonial magic as the god of silence, secrecy, and confidentiality. Originally a symbol of the newborn sun and childhood in Egypt, his iconic gesture of a finger placed to the lips was misinterpreted by Greeks and Romans as a command for silence, transforming him into a guardian of arcane mysteries.