When the Soul Enters the Body

The aspect changing with destruction dread,
She makes the living pass into the dead.
Εκ μεν γαρ ζωων ετιϑει νεκρα ειδε αμειβων.

And again,

For this I weep, for this indulge my woe,
That e’er my soul such novel realms should know.
Κλαυσα τε και κωκυσα, ῶων ασυνηϑεα χωρον. Empedocles

Speaking of Souls Unembodied

We live their death, and we die their life.  Ζωμεν τον εκεινων ϑανατον, τεϑνηκαμεν δε τον εκεινων βιον. Heracleitus

Apuleius’ Testimony on Initiation into the Eleusinian Mysteries

I approached the confines of death: and having trodden on the threshold of Proserpina returned, having been carried through all the elements. In the depths of midnight I saw the sun glittering with a splendid light, together with the infernal and supernal gods: and to these divinities approaching near, I paid the tribute of devout adoration.

Generation of the Soul

The soul descends Corically [or after the manner of Proserpine] into generation, but is distributed into generation Dionysiacally,  and she is bound in body Prometheiacally  and Titanically: she frees herself therefore from its bonds by exercising the strength of Hercules; but she is collected into one through the assistance of Apollo and the savior Minerva, by philosophical discipline of mind and heart purifying the nature. – Olympiodorus