"Chthonic Hermes, who oversees over the dwelling of my ancestors, come, preserve and aid me, now that I am returning from outside of the boundary. I am at my father's tomb, Hermes, calling him to hear my invocation and present himself".

That are the first verses of...

... Aeschylus's "The Libation Bearers".

The chthonic Hermes is, of course, the sum total of the ancestors. The dwelling of the ancestors is, of course, the barrow. Orestes ("mountain dweller", ergo the fetus in the womb, the initiate in the cave). Orestes calls Hermes...

...to come, id est he asks for the ancestral spirit to be revived inside him. His return from "out of the boundary" means that he will return from the realm of the dead to the realm of the living. The father to whose tomb he is, at the literal sense, is the tomb of his...

..biological father, Agamemnon, but, the "father" in the symbolic sense is the previous incarnation, the forebear to whose barrow he descends. Him summoning his father/forebear means, of course, that he rekindles the sacred flame. He is himself given to himself, so to speak

Dixi