"'You talk like the Sphinx, sir, but I am not afraid.'"
Oedipus and the Sphinx (1864)
Creative Commons Attribution Share AlikeOedipus and the Sphinx (1864) - Credit: Gustave Moreau (photo: Ed Uthman, Flickr)

The concept of the sphinx existed in both Ancient Greece and Ancient Egypt: the Greek version was a malevolent monster who punished the people of Thebes by setting a riddle and then devouring  those who were unable to solve it; the Egyptian version was a more benevolent guardian of tombs or religious temples.

The Greek Sphinx had the face and breasts of a woman, the haunches of a lion, the wings of an eagle and a serpent-like tail whilst the Egyptian sphinx was generally depicted as a man with a lion's body.

In common parlance, the term 'the Sphinx' often refers to the Great Sphinx of Giza situated on the Giza Plateau on the west bank of the Nile.

Sandy seems to have the Greek Sphinx in mind as she holds her imaginary conversation with Mr. Rochester.

The Great Sphinx of Giza
Creative Commons Attribution Share AlikeThe Great Sphinx of Giza - Credit: a rancid amoeba, Flickr