The silence that enfolds something kept unsaid points to the unsayable. By being wrapped in silence, what is arcane (kept hidden) comes to participate in what is esoteric (by its nature inexpressible). The secret becomes a symbol of the mystery, participating in what it points to, by the way in which it points to it.
Earl King, Jr., Having and Keeping Secrets: Some Words About Silence and The Hermetic Art of Secrecy