"But I will tell you another thing, son of the all glorious Maia and Zeus who holds the aegis luck bringing genius of the Gods. There are certain Holy Ones, three sisters, born of a virgin with winged heads besprinkled with white meal, and they dwell under a ridge of Parnassus. These are the teachers of Divination apart from me....From their home they fly now here, now there, feeding on honey-comb and bringing all things to pass. And when they are inspired through eating yellow honey, they are willing to speak truth; but if they be deprived of the gods' sweet food, they speak falsely, as they swarm in and out of each other. " 

Homeric Hymn 4, from line 550, translation by Hugh Evelyn-White