Plutarch, De Iside et Osiride
Goodwin, Ed.

The story is thus told after the most concise manner, the most useless and unnecessary parts being cut off. They tell us how that once on a time, Rhea having accompanied with Saturn by stealth, the Sun found them out, and pronounced a solemn curse against her, containing that she should not be delivered in any month or year; but that Hermes, afterwards making his court to the goddess, obtained her favor, in requital of which he went and played at dice with the Moon, and won of her the seventieth part from each day, and out of all these made five new days, which he added to the three hundred and sixty other days of the year; and these the Egyptians therefore to this day call the Epagomenae (or the superadded days), and they observe them as the birthdays of their Gods. Upon the first of these, as they say, Osiris was born, and a voice came into the world with him, saying, The Lord of all things is now born. There are others that affirm that one Pamyles, as he was fetching water at Thebes, heard a voice [p. 75] out of the temple of Jupiter, bidding him to publish with a loud voice that Osiris, the great and good king, was now born; and that he thereupon got to be foster-father to Osiris, Saturn entrusting him with the charge of him, and that the feast called Pamylia (resembling the Priapeian procession which the Greeks call Phallephoria) was instituted in honor of him. Upon the second day Arueris was born, whom some call Apollo, and others the elder Horus. Upon the third Typhon was born, who came not into the world either in due time or by the right way, but broke a hole in his mother's side, and leaped out at the wound. Upon the fourth Isis was born in Panygra. And upon the fifth Nephthys, whom they sometimes call the end, and sometimes Venus, and sometimes also Victory. Of these they say Osiris and Arueris were begot by the Sun, Isis by Hermes, and Typhon and Nephthys by Saturn. For which reason their kings, looking upon the third of the Epagomenae as an inauspicious day, did no business upon it, nor took any care of their bodies until the evening. They say also that Nephthys was married unto Typhon, and that Isis and Osiris were in love with one another before they were born, and enjoyed each other in the dark before they came into the world. Some add also that Arueris was thus begotten, and that he was called by the Egyptians the elder Horus, and by the Greeks Apollo.