Passage 6.20.2
ἐν δὲ τοῖς πέρασι τοῦ Κρονίου κατὰ τὸ πρὸς τὴν ἄρκτον ἔστιν ἐν μέσῳ τῶν θησαυρῶν καὶ τοῦ ὄρους ἱερὸν Εἰλειθυίας, ἐν δὲ αὐτῷ Σωσίπολις Ἠλείοις ἐπιχώριος δαίμων ἔχει τιμάς. τὴν μὲν δὴ Εἰλείθυιαν ἐπονομάζοντες Ὀλυμπίαν, ἱερασομένην αἱροῦνται τῇ θεῷ κατὰ ἔτος ἕκαστον· ἡ δὲ πρεσβῦτις ἡ θεραπεύουσα τὸν Σωσίπολιν νόμῳ τε ἁγιστεύει τῷ Ἠλείων καὶ αὐτὴ λουτρά τε ἐσφέρει τῷ θεῷ καὶ μάζας κατατίθησιν αὐτῷ μεμαγμένας μέλιτι.
At the extremity of the Kronion, towards the north, between the treasuries and the hill, there is a sanctuary of Eileithyia, and within it Sosipolis, a native deity of honor among the Eleans, receives worship. They call Eileithyia by the surname Olympian, and each year choose a priestess who serves this goddess. The elderly woman who attends Sosipolis holds her office according to the sacred custom of the Eleans; she personally brings water for bathing the god and arranges cakes kneaded with honey for him.