The term sibyl comes (via Latin) from the ancient Greek word sibylla, meaning prophetess.
The Greeks further state that she was the first woman to chant oracles; that she lived most of her life in Samos; and that the name Sibyl was given her by the Libyans.
Serapion, in his epic verses, says that the Sibyl, even when dead, ceased not from divination.
He writes that what proceeded from her into the air after her death was what gave oracular utterances in voices and omens; and on her body being changed into earth, and the grass as natural growing out of it, whatever beasts happening to be in that place fed on it exhibited to men an accurate knowledge of futurity by their entrails.
[3] Plutarch tells the story that Alexander the Great, after founding Alexandria, marched to Siwa Oasis where the Sibyl is said to have confirmed him as both a divine personage and the legitimate Pharaoh of Egypt.